The smaller the gun, the bigger the experience to shoot them well! This is the paradox of carry guns versus shooting guns.
If she is going to carry in her purse a, Lady Smith or similar style with steel frame would be suitable, as it has enough weight to tame the little wheel gun, and still compact and easy to carry. The super light Smiths, especially scandium (fancy aluminum) framed guns are very light, easy to carry, but they are harder to control and cost much more.
Again, for purse carry a 3-inch barrel may be better, easier to control, and have a longer sight radius for more accuracy, at least when practicing! The grip size is adjustable via different grips on the market, and her shooting tolerances can be tweaked using various ammunition brands and styles! The short of it ... target loads, which are light on the power range for practice, and full loads for carry. If she is a real tomboy she may be able to shoot +P ammo, more powerful than standard loads, and only carry those after a little familiarization training with them!
First decision ... how will she carry it? Women/girls do not like guns tucked into their pants, they have small waists, and thin pants and shirts on. This is one advantage of super light guns, they hide easy because they don't pull the pants down, and can be carried in jacket pockets easily as well. If they feel the gun is a burden, they won't carry it, I assure you. I couldn't get female cops to carry either a backup gun on duty, or a real off duty! Girls are concerned with their small frames with the visibility of it, bulging and printing through their clothes, and their physical limitations of their small frames to support big guns, or heavy guns! I have dealt with this issue for years!
Keep it simple, as light as she can handle when shooting, and most of all it must reliable. The other rule IT MUST BE EASY TO CARRY IN LIMITED SPACE, WOMEN AND MEN SEE THIS DIFFERENTLY.
REMEMBER, a .32 in her hand, if it comes down to that, is better than a .45 in her glovebox, or worse--at home! Be flexible!