Now I understand sister better. Parents are afraid that their daughter will become like her brother, and that's why they push her even more to be feminine. Although she does things that are not necessarily a sign of gender dysphoria, the father already presupposes that she could become like his...
She is "lesbian" for her hatred of men. It's not that she loves someone of the same sex and that's why she needs people to accept their relationship, is that she runs away from men. Marriage because of hate, very good.