Most Helpful Girl
I think you should have already told her.0THIS IS NOT RELEVANT ANYMORE
Most Helpful Guy
From a relationship coaching lens, here are my thoughts:
1) Asking her out on a date IS telling her you are interested in her and it gives her an opportunity to accept or decline--that date that is.
2) When you straight up tell someone that you like them, you are only giving them an opportunity to respond "yes" or "no" to that specific, indirect question: Do they like you back.
3) By asking her out on a date, which I recommend, you are giving her an opportunity to address the date and to get to know you even better via the date.0THIS IS NOT RELEVANT ANYMORE