Training!!
Get her some training. My wife went to an all women's class put on by the NRA and loved it. She got to try out a lot of guns from 22-45 acp. THEY, not me, taught her proper grip, trigger control, sight alignment, etc. The information coming from another really helped her learn the basics.She also had a nice time learning with a bunch of her peers. Currently her favorite gun to shoot is our Wilson 1911 in 45 acp.
My guess is that your gf is flinching because of the recoil. Dry firing will help a lot, IMO.