I agree with letting her try some out for herself as much as is possible.
I'm a retired (code for "older," LOL) woman with small, rather weak hands. Here are a few factors she might want to think about:
How "into" firearms will she be and how often will she go to a range to use one?
(For those for whom the answer would be "rarely" and it just sits in a drawer, I'd suggest considering a DAO revolver in .38 spl, because it is more intuitive to operate and simpler for the inexperienced user who seldom touches a firearm. It's also less prone to user-caused malfunctions. The heavy trigger pull can be a safety and comfort advantage and most women can use both index fingers to pull the trigger if needed. I find myself automatically doing that at the range after the first several shots if my finger gets tired, and it doesn't affect my accuracy.)
Will she be able to confidently rack the slide on most semi-autos?
(I can, but I have to grip the top of the slide using my entire non-dominant hand, and then push the frame forward at a downward angle using my dominant arm. Arms are stronger than fingers. It took some practice but even I can do it easily now, so she can probably learn to do it too. However, this can be a real problem for some, and if she's not comfortable operating the handgun she's not going to enjoy or feel confident using it. If that's the case the Shield EZ might still work for her.)
Is she more comfortable with a pistol that has a manual safety, if it's not a true DAO with a heavier trigger pull?
(Even though I always keep any loaded handgun in a holster, even in a drawer, I've learned the hard way that I simply prefer a striker-fired pistol to have a thumb safety, but she may not want one. This is personal preference.)
Considering the above, here are some models I'd suggest considering:
S&W 642 or 442 .38 spl revolver, or a bigger 6-shot model (not a bigger caliber) or something similar. I also like my Ruger SP101 loaded with .38 spl.
(I keep these loaded for home defense.)
M&P Shield EZ in 9mm, or maybe even .380
(The slide is easy to rack on these and they are a little larger than the regular Shields which also helps with recoil. They are available without or with a thumb safety. Unlike the other Shields the EZ has a grip safety.)
M&P Shield Plus in 9mm
(I keep one of these loaded in my home. It's probably my favorite pistol to shoot, too. The smaller, somewhat oval grip fits my hands better than the double stacks including the Glocks. But it also has a stiff slide. It's also available without or with a thumb safety.)
M&P 9C double stack, or something similar
(This is also one of my favorites, and the one I did very well with when I took my county's optional firearms course.)
Any of the 9mm Glocks or a similar semi-auto; many choices out there.
If she doesn't like 9mm or a revolver, look at some .380 ACP models.
One tip on gripping a handgun:
In addition to a very firm two-handed grip around the pistol, it helps me if I also press my hands toward each other and the sides of the firearm. Maybe everyone does this, though?
Best wishes to both of you in finding a firearm she likes and enjoys shooting.