Hi TL4everu2, I hear you. We actually specifically told Mia not to tell her mother, but she did it anyway, and the consequences were dire and things got really ugly. Apparently she had a great relationship with her mother until that point, so she thought that her mother would be happy for her, as naive as that sounds. I agree with you that there is no need for everyone to know.
As for your question, it was my gf's decision to pursue the triad, specifically the FFM. Before I met her, I didn't even know there was such a thing as polyamory... She did the research and we discussed it at length, and it took me some time to get comfortable with the idea. Anyway, she has a definite preference for women and do not find (most) men attractive, so FMM seems highly unlikely, even though we have never ruled out the possibility.