I think Marie healed her mother and Cipher knows

Marie’s aunt told Marie about how she was IVF with the help of Vought, but that her younger sister was the “real miracle” because it was a natural pregnancy. Fetuses share a blood stream with their mothers, so Marie might have healed her mother’s infertility (while she was in the womb).

If Marie really is capable of healing people, then she really would be one of the most powerful characters. It could also be why Cipher is so interested in what she can become. He would be the person who knows best what happened to Marie’s mother, since he was her doctor at the time.