Ummmm someone help?

My little sister (11) just told me she is Bisexual which is no problem to me but if our parents find out they will look at her as the biggest disappointment along with the rest of our family and I don’t want to tell anyone but I don’t want them to find out since she just recently got a phone and idk what she talks about I think I’ll just tell her to be cautiously what she says regarding that because she already knows that all he*l will break loose if anyone finds out