I understand. There isn’t really a telltale sign that a girl may want to be asked out unless she tells you outright. If you two are good friends and enjoy each other’s company then that is a good enough benchmark. It’s just a shot in the dark you’re going to have to take. You can start small like a casual movie “date” or bowling, Ice cream or whatever seems fun to you and build from there. It’s important to emphasize it as a 1 on 1 event and not a friend group thing. If she is down then take your time with it, if not then you are smart enough to realize what it’s going to be.