There is a very simple rule in regard to women fncying men - one which every man should learn and stick to, and it's this -
If a woman wants you to come on to her, she'll let you know."
Women are experts at reading signs, so the chancea re she will know tou find her attractive. If she is not giving you signals that she'd like you to ask her out, then it's because she sees you as a friend, and is not interested in anything else.
The signals - non-verbal - are smiling at you and holding eye contact. Standing or sitting close to you. Touching you without needing to - a hand on your arm, that sort of thing.
The signals - verbal - include talking about outside interests in an inclusive way - "I like going to the cinema / theatre - how about you? That sort of conversation.
If you are not getting any of this, it'e because she is not putting it there, because she isn;t looking for you to act, so keep your dignity, and enjoy her friendship.
Things may change - keep your eyes open, but remember the golden rule which men break on a daily basis - just bcause you fancy her does not mean she fancies you back.
Hope this helps.