Man, next time you have a private moment with her, kiss her.
Don’t ask her friend or stuff. Make you own decision. She clearly likes you and you need to sort out if she is just teasing you or if she’s waiting for something more.
Be a man and take it to the next level.
If it works: congratulations.
If it doesn’t: you have been a man and made things move which is great for your experience.
Clearly: make a move.