Unlike Andrea (Millet's niece), both say they want to become the Mother, if the gods choose to smile on them. Those close to the women say that, despite their family ties, there is a bitter rivalry between them, made worse by the intense speculation surrounding Andrea's position in the Gantois.
Mother Carmen, as she is already known, is, at 62, the elder and more traditional of the two. Overweight and suffering from ill health, da Silva has temporarily assumed some of the more pressing responsibilities of the Mother's position. Sitting on a wooden chair in the Gantois, she obliquely explains how the leadership of the House lies in the lap of the orixas. "The orixas have to choose and it takes many years for them to do this with proper care," she says impatiently, her voice lowered to a whisper. "You have to be very patient. Very patient indeed."
It is a Friday, the day devoted to the chief spirit of the orixas, and da Silva is clad in white. She is still prettily cute, despite her age and weight, with a small nose, playful eyes and rosebud lips. Because her father had British blood in his veins, her skin is the palest black. Da Silva rarely comments publicly on her religious beliefs and staunchly refuses to meet most journalists. When she was first approached for an interview, she claimed to know nothing about Candomble. After several more calls, and the help of an intermediary, she agreed to an informal chat.
The atmosphere around da Silva, who is encircled by believers kneeling in homage, is one of intense holiness. Everything is silent; even the air has stilled itself. At first she does not deign to talk and avoids questions like the deftest politician. But after staring intently into the new faces before her she says: "The buzios [the sacred fortune-telling seashells] will tell all. I've had experience with them when my mother died and my sister was chosen. They know more than anyone. Any daughter of the family could be the One. They know me more than I know myself. They know my limits." Her voice fades and is swallowed by the silence.
Minutes pass by and nothing is said.
"It's a complex thing," she says at last. "The buzios might prefer someone younger but we cannot close the House for 10 years and wait for her."
On this point, Monica Millet agrees with her aunt. She concedes that even if Andrea is chosen by the orixas in the buzios game, someone else from the family will have to take care of daily affairs until she learns to meet all the responsibilities the position requires. As befits the generational difference between the two women, Millet would make a more modern and infinitely more down-to-earth Mother than da Silva. Rather than being soaked in the old traditions, she sees herself as the Gantois's reformer.
Although she doesn't dissuade believers from kissing the floor when they enter her presence, she is determined to haul the movement into the 21st century.
A 41-year-old musician who has worked with some of Brazil's top recording artists, Millet has the gait of a man and the rather incongruous dress sense of a middle-aged housewife. She is also the daughter of the last Mother of the House, Mother Cleusa.
Along with her aunt, Millet has been helping to keep the House going during the period of self-enforced mourning.
"Since my mother died it has been very difficult because people keep asking who will be the successor. There have been many arguments and a lot of politics inside the House," she says candidly, "making it difficult to maintain ordinary things here."
Millet explains that when a Candomble House loses its Mother, it is as though all the believers lose their real mother. The mourning period is long and difficult, not least because the House can barely function without its spiritual leader.
"It takes us a long time to accept the death of our old Mother and adapt in a human way to another person being in charge. But soon the time will come for the orixas to choose. And when they do, the old people who have passed on to the other world need to stand up for me. If I am to be the One, I need to be blessed by the spirits of the grandmothers and have the dead on my side.
"It's in all our blood and whoever it will be knows that they have to give their whole life to the House."
Andrea's feelings are different from her blood sisters. The girl is still very much a Candomble novice and despite her illustrious family tree, the Gantois elders expect her to know her place. Dressed smartly in a yellow top - the colour attributed to her orixa - and a short white skirt, she speaks with matter-of-fact shyness about her position in the spiritual line-up.
"It's a little bit embarrassing. When friends at school read about me in the newspapers and things, I feel strange. I'm proud to be who I am because Candomble is my religion," she says peering out from behind her curly eyelashes, "but I want to finish school before I continue the tradition."
The delicate-looking girl used to go to the House every day when her grandmother was alive. Now, despite living just a few minutes' walk away, she tends to visit only when it is time to pay "obligation" - a regular religious devotion of some kind - to the orixas. "My obligation is to cook the white corn that we feed to the orixas during the ceremonies," she explains. "I have to separate the good corn from the bad and sometimes I sew sequins on to our holy costumes."
Despite the mourning period now entering its second year, no one in the Gantois seems to know when the spirits will choose the new Mother. Some, like Millet, say this could be at least one year hence but others, da Silva among them, point to a sacred seven-day ritual that takes place later this month.
In spite of the unquestioning acceptance among the devotees that they just have to wait for a signal from the orixas, a need - even a desperation - is growing within the House. As one elderly woman, who has spent 68 years in the Gantois, explains: "We need our Mother. You must understand we are nothing without her."
In Candomble, the Mother is everything. For a religion built around the concept of subjugation, the Mother of a House is a powerful figure who dispenses guidance on all aspects of her flock's lives. Rather like a modern-day agony aunt with holy status, believers ask for advice on everything from the smallest dilemmas to life-changing decisions.
In Brazil, countless owners of successful companies belonging to the religion regularly consult their Mother on complex business strategies, often refusing to act without listening to her views. This dependency on the Mother is an integral part of the tradition and is fostered from the first day a prospective initiate enters a House.
Marcia de Souza, an African-languages lecturer, joined the Gantois 19 years ago. Describing her former self as bossy and opinionated, she remembers learning to model her behaviour to keep within the movement's ideological dictates. "You have to be very disciplined with Candomble. When you first go into the House, you go through the whole process of being a child again. The elders treat you like a toddler. You have to learn how to eat and how to hold your plate of food. You have to sit in a corner and be very quiet and not speak until spoken to. Like a child you have to ask the Mother for everything and that's why we have such a strong relationship with her. It takes a lot of discipline but it has made me a much calmer person."
This process of rebirth lasts for seven years. After this time, the acolyte takes part in a ritual where the orixas are incorporated into their body. This merging with the spirits allows them to become a son or daughter of the saint. However, full independence, or "adulthood", is not reached for another seven years. "That is why we feel real pain when our Mother dies," says de Souza. "We ask her for everything and you learn to respect her opinion on all aspects of your life. It's very hard for us now because we are so sad without our Mother. All of us get very emotional when we talk about who will be the new leader of the House. But whatever will be, will be."
Andrea was only seven years old when she was thrust unwillingly into the limelight. In an interview on the subject of succession, her grandmother, Mother Cleusa, indicated the young girl was a possible candidate for the position of Mother when she herself died. "It is surprising how gifted Andrea is taking care of the axe [ritual prayer]. She is just seven, but is so dedicated and serious. You don't see a single smile on her face," she said.
Gantois followers say that if chosen, Andrea will have to spend many years in religious training. And although she would be a public figurehead to the House, others would operate from behind the scenes ensuring that the believers will be able to consult a caretaker Mother.
Her father, Alvaro Millet, is determined that his young daughter is not forced into any future responsibilities against her wishes. "It would be bad for her development and for her spiritual mind," he says. "No one will be allowed to force her to do anything. It must come from within. My intention is that she gets a proper education, which may include going to university. If she is to be the chosen One, then she must learn to take care of many, many people, and having an education will help her do this."
For now, though, Andrea can do nothing but wait, like her more powerful and knowing relations, Monica Millet and Mother Carmen. When the spirits choose, the House of Gantois will hold a ritual and play the buzios. Andrea will be there, of course. She will be awaiting her fate; listening for the commands of the orixas and watching to see whether her long-dead line of magical grandmothers stand up in her favour.
Until that time though, she must put up with all the speculation and await the ancient ceremony. The truth about her future remains hidden. For the moment only the spirits know.
And they aren't telling.