^^ Just ask her to come round to yours for a movie night, or out for dinner or something, just the two of you.
Spend some time alone with her, and see if you can work out if she likes you.
If you still aren't sure, then just ask her if she would be interested - tell her you really like her and you think you wanna be more than just friends and want to know how she feels about that
In other news, on the 18th of this month it would have been mine and my ex's year anniversary!
BRING ON THE DEPRESSION xD