My younger sister just came out to me as bi

So, I was having a conversation with my sister (she’s 12) and she brought up that she has a crush on her friend but doesn’t want to tell her and ruin their friendship. My first reaction was “wait what” because she’s 12 and doesn’t need to be dating. (I’m 16). So she repeated herself. This time saying “I have a crush on this girl who’s my friend. I want to tell her but I don’t want to ruin our friendship”. So again, I was like “wait WHAT!?? Oh I wouldn’t tell her ive been there and it ruined my friendship.” so we finished our conversation and she left the room. Then it clicked. I was like whoa. Wait. She’s bi? (She’s had crushes on boys in the past) so, I’m bi but I’ve never like, formerly came out but all my friends know and so does my sister. so I haven’t brought it up to her since. I obviously support her 100%. But should I bring it up to her? should I leave it alone? I don’t want to make it awkward but then again I don’t think it’s a huge deal or something that I need to confront her about. I don’t know. This is a mess but I’m also half asleep lmao