TheKid,
A defensive handgun, by definition, is a weapon intended to save your life, or in this case, your parents' lives. Think of a defensive handgun as a tool to escape danger, not confront it.
In my opinion, the smallest caliber I'd use to save my life is .38 Special +P. But since I don't like the idea of going with minimum for saving my life, I'd prefer either a Sig P-229 chambered for .40 S&W or a 1911A1 chambered for .45 ACP.
In my opinion, the Model 1911A1 chambered for .45 ACP sits alone at the pinnacle of self-defense handguns. However, there is tactical advantage to not having to reload. Hence, 13 180 grain .40 S&W LE rounds in a P-229 with 12 more ready to go in a couple seconds makes it close to a dead heat. A full-size Model 1911A1 and a Sig P-229 are not difficult to conceal.
The only known way of surviving a gunfight is to not get in one. If that's not possible, the next most important rule is to not get shot. A good guy would be in a gunfight because a bad guy wants him dead. And dead is as final as it gets.
Every human being is declared dead when there's lack of brain activity. That can occur via one of two modes: destruction of the brain or lack of oxygenated blood to it. In the latter case, it means reducing a bad guy's blood pressure to zero.
In a gunfight, especially at close range (<10'), if you don't get the heck outta a bad guy's sight picture, you're probably gonna take rounds. That's never a good idea. Hence, suppressive fire while running for cover is a wise tactic. That means lots of rounds.
If you're lucky enough to hit a bad guy, you have to inflict as much damage as possible, which means go big, as in caliber.
I own no defensive handgun smaller than a .38 Special. I'll never own a pocket gun. Now that's just my opinion. You do what's right for your parents and you. I don't much like the idea of having to rely upon a 5-shot .38 Special loaded with the FBI load to save my life. If I'm carrying a handgun, which I rarely do (I can legally carry anywhere the American flag flies), it's almost always my old duty weapon: my Sig P-229.
My life is damned important to me. I avoid going to places that are dangerous. I'll go to LA only if I HAVE to. But were I to go somewhere that I thought could be dangerous, I'd take my P-229. However, I'd feel just as safe with a 1911A1.
One more thing to keep in mind: bad guys rarely do bad things alone. That means that, God forbid, were your parents confronted by bangers, there are better choices than a pocket pistol.
Were I to buy another handgun for self-defense, it'd probably be a Sig P-239 in .40 S&W. Also, I like heavy for caliber bullets. I don't read ballistic tables. I want momentum. If one hole is good, two have to be twice as good. I want a lot of blood out hastening zero blood pressure. At least that's how I have it figured. Please understand that these are my opinions. What's right for me might be all wrong for another.
I wish your parents long lives and absolute safety.
Best of luck to you.
