I was taught from the time I started getting money, to put at least 10% into savings. Usually it was more like 30%. Since my family is Christian, I was also taught to set aside 10% for the church. Whatever was left was free to spend.
I also was taught how to handle money well and to handle credit. It is a difficult thing to learn, I think, when one comes into it later, but it *can* be done.
OTOH, is there some particular reason you want her "gone" before she is married? I see no reason, personally, that a young woman should be forced to move out of her father's house before she is moving in with her husband.
At the same time, your question isn't really about her leaving or not, but about responsibility, and that's a similar but different thing
