If your gonna ask her out, don't do a group date. Your gonna get cock blocked and she will think, it's just a bunch of us getting together, nothing romantic about that.
start text again, then after ice is broken, call her, chat for no more than 5 minutes. Ask her "When are you free this week?", if she says she is busy, then let it go.
If she says, "Well Wednesday night I don't have plans", then you make plans. Evening plans, not a lunch date, a night time date, so you can seduce her and get her back to your place.
Ask her out 2 times, over 2 weeks, if both times she can't, then tell her, "No problem, give me a call when you have some time, I know this awesome place I ant to take you too."
That is it. Don't call, don't text. Only contact her is she contacts you first. When she does contact you, get back to her and ask her out. If she says "I'm busy", end the phone call with "I gotta go, but call me when you have time to get together".
Then don't call, don't text.
Meet some other girls that want to do stuff with you.