My male ex, who is also a co worker to the sister of my female crush, that I liked her.

So I used to work at a burger place and, after breaking up with my ex, I ended up having a crush on another co worker who happened to be female. Me and my male ex ended up being close friends so I told him about her. About a month after I left, I get a friend request from the female crush. So, I of course accept it. Me and my male ex were talking and I happened to ask if he had said anything to her about my crush on her, because he was the only person at my workplace that knew about it. And come to find out that he told her sister and my former boss. So now of course she knows. So as far as I knew she was straight. She suggested that I date my ex in the first place and she never hinted that she might be gay. And Mormon
So idk If I should message her or just leave it up to her to message me.