Exactly!
I'd say. Show some balls and try to escalate. Start off with some kino, make her think about You in a sexual context. Touching is a good way to go but also talk with her implying she's very attractive.
But for god sakes NEVER, EVER talk about Your ex. She might try bring her subject up (especially that they are friends). When she'll ask or say that it's wrong between You two just say something like "Well I can't say a bad word about her but I guess we just didn't quite fit together", say it with a tiny smile like it doesn't hurt You anymore and You're just cool with that and just change the subject.
I start using line
"I can't say a bad word about her. I guess we didn't quite fit together" whenever someone asks me about my ex and they're all surprised what a positive attitude I have.
Just something I thought You'd want to keep in mind

.