I like her and I think she likes me but the thought of being kind of like her kids "father" weirds me out a little, I mean I know I'll be a father one day but I don't think that right now during high school would be so beneficial.
Take your time to think about it. Get to know her better. You can start off being her close friend, being there for her and helping her out. If you're having these thoughts now, it's better to put off a relationship with her for a while and focus on your studies instead. You've got a future ahead of you, unless she's really worth it, you should not let it become a burden to you too soon alright.
It is a lot to ask you to be a father to her kid implied or not. If you are not comfortable with the idea, then it has already put a strain on a potential relationship. I'm not saying men dont end up with a woman who has kids from a previous relationship, but at your age its better not to go into it. However, if you really want to, give it a go, you never know what could happen. :D