I think all the responses of everyone else is ignoring one thing... she said that money is "tight". Therefore, I suggest that she keep the 22LR revolver that she already has. You want something small, accurate, reliable and light. You're familiar with the gun, so you're accurate with it. Plus 22LR ammo is cheap. That's important since money is "tight". I bet that a 22LR revolver is much lighter and smaller than any "real" defensive pistol. Revolvers are real reliable to boot, too. And to the poster that suggested that the OP go to a gun store... do you work in a gun store? Gun stores have to make money so they're probably gonna "trade" her $500-600 revolver for a $250-300 Kel-Tec or S&W Sigma. That means she's lost $300 in the deal. If money is "tight", how can she afford to lose $300?
I suggest that you Keep the 22LR revolver that you already have and get a CHL when you can afford it. For now, go to the range and practice with that revolver. Being a crack shot with a 22LR is much better than being a bad shot with a 45ACP. Lots of people successfully defend themselves with "just" a 22. Yes, I know, it's a horrible self defense caliber, but remember, the most important piece of equipment you own is NOT the gun, but your brain. Keen situational awareness and a good flashlight will keep you out of trouble 99% of the time. The average perp is not someone high on acid that will keep attacking after being shot multiple times. The average perp is looking for an easy score. No perp is going to think that a gunfight is an easy score. I'll bet that just hearing a "bang" and seeing a gun is enough to make most perps run. The gun is the LEAST important item in your self-defense arsenal because it is your LAST resort.
For self-defense practice, I suggest that you go to the next Dallas Pistol Club competition and participate. These are great events to go to because your shooting technique will be critiqued by others. It's like getting free instruction and training. Spend your money on range fees and ammo to become a more effective shooter. Live life in condition yellow (be aware of your surroundings).
The next step is to get your CHL. This can take months (mine took 9 months!), so it's best to get the ball rolling on this as soon as possible.
The LAST step is to get a new gun. You can wait until your tax refund or a raise at work to get that. Buying a gun is easy and takes just minutes, so it's not necessary to get the ball rolling on this now. Just wait until your finances are better.
Would I use a 22lr for self-defense if it was all I could afford? You betcha! Having a gun is better than not having one, regardless of caliber. Besides, 22lr kills more people than any other caliber (due to the fact that the round is so cheap and plentiful). Due to 22lr having zero recoil and guns in 22lr are real light, I can fast draw my 22lr glock and shoot half a dozen shots into a quarter at 10 feet in under 1 second, roughly. I couldn't even do that in my dreams with a real 9mm glock. The width of a human spinal column is roughly the width of a quarter. Hmmm....
Million mom march against guns participant hated her husband's gun. After she used it to defend herself against home invaders, she's now an advocate of the 2nd Amendment. Being anti-gun, she only allowed her husband to keep a 22lr revolver in the home. After she shot the BGs, she had an "epiphany":
http://www.kc3.com/self_defense/susan_gonzales.htm
Papa Johns delivery guy successfully defends himself against
TWO ARMED MEN with a
2 shot 22lr derringer. On a pizza delivery guy's minimum wage salary, that was all he could afford. This was in Lufkin, Texas:
http://www.usacarry.com/forums/general- ... bbers.html Nobody wants to have a gunfight with 2 armed men using a 2 shot 22lr derringer. However, if you have to choose between buying an expensive high caliber gun with no money left over for ammo and range fees or keeping the 22lr that you have and practicing enough to become a crack shot with it, I invite you to notice that the latter choice is wiser.
P.S. famous gunwriter Chuck Hawks recommends that if you use 22lr for defense, then you should use CCI stinger or Remington yellow jackets.