So far all I see is a Mary Sue. Most people don't know what a Mary Sue is and just call powerful female characters that but this is an actual one. Let's check the list, Very young and powerful without having struggled at all for her power(seems like it due to her easy going demeanor), does strange things/breaks the rules with no consequences, everyone loves her within first glance regardless of first impression, is better than literally everyone else in her age group, male characters can't help but to fall in love with her and she had an edgy name like Darkstar even though her powers are based on heat and flames while stars are plasma... Were those all? I think so.

But even with all those things she doesn't have to be a Mary Sue, but she is and do you want to know why? it's because she has almost no downsides. Oh wait, her flames are a scientifically impossible color, normally this wouldn't be a problem but due to this being BNHA where things usually make sense in a scientific way well...

I see potential in this. Especially when you introduce her more.