how long should i wait

I like to go with a month as a rule of thumb. Your mileage may vary.

I once told a girl, who was seeing a friend, that I really liked her. I was drunk, and as soon as the words were out of my mouth, I felt awful. What had I done? Potentially pissed off two people! Oh no! She looked at me for a minute (a very long minute!) and then said, "You need to know, Centrox, that we can't be anything to each other until I split up with Andy." I said, "When might that be?" She replied, "I don't know, a week or two maybe." Boy was I pleased. I was young, and nowadays I would think "Easy come, easy go". By which I meant that it was a couple of weeks and then we were together, but it didn't turn out well. I would say like Jespah, a month at the minimum.

What is your current relationship with her? Are you already friends?

Why don't you know where she is about dating?

If you actually TALKED to her - face to face - you might find out where she is in her life and if she's ready.

Can you not just ask her out for a simple lunch or coffee? You don't have to launch immediately into a full blown committed monogamous relationship. Just go have fun, be friendly, maybe flirt a little and see where she is. She'll either reciprocate or not. If she doesn't seem "ready" just keep it casual and see if she comes around.

Until the cock crows.

shes my cousin best friend ive always like her I just never have asked her out because she was always with her old bf in the past she recently broke up with him because he had to many drinking issues and didn't want to change

Let her know that she may think it's too early now, but when she is ready you'd like to take her out.

do you know this from talking to her?

when was the last time you had a conversation with her?

I know this because my cousin is her best friend and its been a little while since ive talked directly to her I just don't want to rush in but i don't wanna wait forever and someone else ask her out if u know what I mean I recently applied for a new job and actually she works at the place I applied for I hope I can slowly start talking to her more and ask her out to lunch or something

Call her and tell her you want to talk about the place you applied to.

Invite her for a coffee.

Separately - tell your cousin to stop gossiping - and don't listen to gossip. If you encourage the gossipers , you'll be next on their discussion list.

You could start talking to her earn her trust and respect and so forth.