It‘s very hard to choose a gun for someone else. What works for one person will not work for someone else. This is definitely something she is going to have to figure out for herself (maybe with some guidance from you or an instructor). Have her shoot some different pistols at the range to help her make up her mind.
The one thing I would try to gently steer her clear of is a .380 or below (but if that’s all she will carry, it’s better than nothing). If she goes the .380 route, there are plenty of offerings from Ruger, SIG Sauer, Kahr, Taurus, Kel-tec, etc…
I would try to point her towards a 9mm at a minimum (Kahr, Ruger, Kel-tec, Rohrbaugh, etc.. all make great pocket pistols). There are also a lot of really good revolvers out there in .38 special that she should take a look at (it takes some decent practice time to be accurate with them – be advised).
My wife was really set on a .380 semi-automatic due to its size. Once she took a self defense course her mind changed as she realized the limitations of that caliber in terms of ballistics and her accuracy/skill level at 25 yards and beyond. She now carries a Glock 26 in an IWB holster in which she is pretty competent. The G26 is not considered by most to be a pocket pistol but she was willing to make the comfort sacrifice to gain the extra performance. Choosing a carry gun is all about compromise as most will tell you. It’s up to the individual to decide on what works for them.