Does she want a gun purely for self-defense or does she want to become a "shooter/gun enthusiast", because they are two very different things.
If purely for personal defense and she is not experienced and doesn't plan on really spending much time training, seriously consider a enclosed hammer j-frame revolver like a Smith & Wesson 642.
These guns are simple, safe, lightweight and handle neglect well. Purse carry perhaps isn't ideal, but these little revolvers handle this environment very well as no lint or debris can get into the action and she could even shoot through the purse if need be. You don't want or need single action/an exposed hammer on a self-defense gun...it's a liability in every way. Snubs are not long range range/target guns capable of marksmanship accuracy, but that doesn't really matter as civilian self-defense scenarios happen at very close ranges so there's no need to be a sharpshooter. They do suffer from low capacity, but stats show the vast majority civilian defense encounters involve very few shots. Most(90+ %) follow the rule of 3's as the averages work out with most armed defense scenarios occuring approximately within 3 yards, are over within 3 seconds and are resolved in 3 rounds or less.
In close quarters, the snub is extremely quick to bring into action, especially if talking purse or pocket carry compared with autos and would offer better weapon retention against disarms(a bad guy,mugger, racist trying to take her gun)than any other firearm and you can press the muzzle against the assailants body and the gun will still function whereas a semi-auto's slide would get pushed out if battery. In civilian self-defense scenarios, making contact with assailant/grappling or otherwise getting into a physical struggle is common, so it's wise to prepare accordingly.
Another consideration is that a revolver cannot be limp-wristed. With woman, limp-wristing is actually a fairly common occurrence, especially with polymer pistols(the lightweight frame is the problem) even at the range using a two handed shooting from a stance. During real defense scenarios, one handed shooting is common as is having a less than ideal grip on the gun. Shooting on the move or from a compromised position is common as well so the chances of induced malfunctions by not providing good support for the pistol to cycle would be much higher.
