How to approach this situation? Please help!?

So me and this girl at uni just finished a class together. We were partners the whole semester for activities and got along really well. Towards the end of the semester, we ended up having coffee together for about an hour and a half just talking about random stuff. It wasn't officially a date. What makes the situation difficult is I'm a senior and she's a freshman. We have a lot of interests in common and it seems to me that we both genuinely like each other. Unfortunately, we are currently on winter break so neither of us are at uni.

Aside from the one time we had coffee, the only times we've seen each other has been in class. Is it too soon to ask her out? If not, then how should I go about asking her? Please help, thanks.