My choice - SA XD9 SC
Hi, I am a medium build female and have shot many different guns before I chose mine. Glock, Taurus, S & W (M&P), Ruger, Charles Daly, CZ, Bersa Thunder, etc. None of them felt perfect until I got my hands on the Springfield XD9 compact. Ideally, it would be best to shoot many before deciding but if that's not possible take her to a gun store with a large selection and have her try the grip. It needs to feel good to her. I found the trigger reach to be important to me, then how my hands gripped it and how it lined up (my arms and the sight alignment.) Hope this helps.