Before you lay down your hard earned money, I would strongly recommend that she fire any weapon you plan to buy her.
Just going to the gun shop and letting her handle it isn't enough, IMHO. She needs to know how it's actually going to handle during firing.
She might think it "feels just fine" in the store, but may very well be in for a rude awakening when she actually fires it, and finds out she doesn't like it even a little bit.
If she doesn't like it, it's a safe bet she isn't going to use it. So you'll essentially have wasted your money.
If you don't know of a good range that rents weapons in your area, inquire at each gun shop that you and your girlfriend visit.