I'm not female, but my grown daughter still shoots with me and I help select and maintain her gear.
I would not automatically gravitate toward smaller packages. While most folks are quick to suggest something dainty "just because", my daughter actually does substantially better with a heavier gun for several reasons.
First, the smaller guns might be easier to *hold* in some ways, but are usually harder to *shoot*, due to more pronounced reaction with recoil and muzzle flip.
A heavier gun tends to stay on target better during both the trigger squeeze and recoil, which promotes the feeling of better control (and control IS better). My daughter started out shooting three-gun competitions with my P-01 and did OK, but going to an SP-01 Tactical (practically identical gun but bigger/heavier) both improved her raw scores AND reduced her elapsed time.
The other reason is functional reliability and heavier guns frequently being more forgiving of operator error. With light guns, even slightly limp-wristing the gun during recoil will often produce short stroking and related malfunctions. A gun with a heavier frame relies less on wrist tension and is thus more forgiving.
With shooting under stress, we often forget some of the simple little items on our mental checklist that we might usually think of. A firm, high grip is just one of these things. Practice and training overcome this, but not everyone wishing to be able to defend themselves are avid shooters, and they may or may not wish to invest any more practice into it than is required to actually fire the handgun. As a shooting instructor (and dad) I see this sort of problem a lot.
One great example of this is that we often shoot aluminum cased CCI Blazer 115s in practice and action pistol matches. It runs flawlessly in four or five CZs we run for various stuff. Blazers do have a colored reputation and not all guns like them. In prep for a match, my daughter and I each fired several hundred rounds of this cheap ammo through a pair of identical SP-01 Tacticals without a hitch. During the match, my daughter had several FTFs that the RO quickly blamed on the "crap ammo". The following weekend, we shot the same pistols and same ammo again in practice, and in several hundred rounds neither of us had one problem. The entire issue was caused by match pressure/distractions and simply forgetting to grip the gun. The good news is that she is getting quite proficient in clearing malfs under pressure.
The only other thing I would offer is the suggestion to keep operation as simple as possible.
I normally recommend a .357 revolver to females who wish to be prepared but do not want an advanced degree in handgunning, due to it's extremely simple "point & click" operation. Another very distinct advantage of a revolver is the need for hand strength and dexterity is not nearly so great as is required for a semi-auto, most notably effort required to rack the slide. Many people, not necessarily women, have difficulty fully cycling the slide, and this problem is exacerbated by smaller semi-autos in larger calibers with their reduced gripping areas and heavy recoil springs. In a defensive gun, we must always be prepared to remedy a malfunction, and that will almost always involve fully cycling the slide in a semi-auto.
I personally lean toward DA semi-autos for my own concealed carry firearm and our home defense guns for exactly the simplicity - not a lot of controls to freak out over, just point and shoot. Again, training and practice overcome most of these issues, IF one trains and practices.
