Reacting to my little sister coming out

Sorry if this is the wrong group, I didn't know where to post it. I'm 25, married with two children. My sister is 15 and still living at home with my mom. She called me today, which she never does (I'm always the one calling, we usually just text). I was instantly worried. "I need to tell you something, promise you won't tell anyone". Oh shit, I thought, now she'll tell me something bad, like she's doing drugs or something. I promised her. "I'm gay" she said. Such a relief. It wasn't actually a surprise for me.

Somehow I've always known. When she told me I said "You're so brave for telling me and I'm glad you did. I'll always support you and I only want you to be happy". That's all I said. Was this good? Should I have said something else? We never talk about feelings and stuff because anytime I try to tell her I'm proud of her, that I love her or express feelings she just cringe and thinks I'm embarrassing and stops talking to me, so I don't do that anymore.

She also told me she tried coming out to our mom, but that she didn't get it and it was hard enough taking that step so she wont try again and I said that she'll find out sooner or later anyway. Our mom is a super conservative Christian, so I'm actually a bit nervous for her. I live many hours away from them, and we have no other family, other than my moms super conservative Christian one. I hope they wont try to "pray the gay away" or some silly shit 🙄

If you have any advice on how to support her while living so far away, without being cringy to her, please tell me. I just had a baby a month ago so I can't go over anytime soon as it's flu season and the pediatrician doesn't recommend us travelling and being inside in public anytime soon as my baby was born small.