@Jude – She should really consider carrying something with a bit more punch that a .25.
Just to be clear, I am not one of those bigger is better guys. Further, I quite understand that a .22 to the head is more effective than a .45 to the foot. However, “stopping power” is a very real thing when it comes to self defense with a firearm. Frankly, popping a couple of .25 rounds into a 350 pound crack head intent on doing you harm is likely to do little in the immediate term other than piss him off (even if you do hit something vital)!
Unlike the movies, the bad guys don’t just fall over dead (or incapacitated) just because you flung a projectile at them. Said projectile has to have the capability to deliver enough correctly placed energy to render them immobile. Sure, you can do this with a .25 if you happen to be able to hit them in exactly the right place while you are literally in fear of your life and in a close up and personal combat situation. However, something with a bit more ft/lbs of energy and a bullet designed to loose that energy quickly on penetration (thus delivering all of it into whatever mass you hit instead of punching a nice clean hole) is much more likely to make the crackhead slow down.
I would highly recommend something along the lines of a compact .40 SW or even a compact .45. Both come in fairly small packages these days and are worth a look. As for bullets, go with a nice JHP designed for maximum expansion.
As my firearms instructor once said: “Never enter a gunfight with a gun that has a caliber with beginning in anything less than the number four.”