I know women who have a genuine, long lasting tendency toward being attracted to other women, who have also been influenced in their perceptions and attractions by the sorts of men they are around and their expectations for what men are likely to provide in a relationship, in both directions. Bad experiences of men in their lives can leave a woman with unusually low expectations for men and may signal them to just lean into a preexisting natural attraction to other women if they have one. Good experiences can leave them realizing there is at least one, realistic, opportunity for them to be with a strong, principled man, and might awaken some dormant hetero leanings.

Girls are frequently bi or bi-leaning. I think it's part of the natural process of evolutionary pressures being very selective about which men get to procreate. It may or may not have been something that helped polygamous relationships in the past to be stable too, like harems and shit. Idk. That's my thoughts from an evolutionary pressure point of view.