Is she completely new to shooting or has some experience?
It's wonderful how you're taking her hand strength and RA in consideration-many people don't.
If she is pretty new, please start her out with a .22 and let her have some fun and get some confidence. Starting out, if she doesn't like the little larger cal's she's tried, don't be discouraged, you've "planted the seed" in her mind and chances are, she will let you know when she's ready to move up!
I personally do not like the KelTec's because of the grip pattern actually hurts my hands while shooting them, so if she has soft skinned hands, that's another thing to consider. Yes, I know I can change them, but I really like my 442
If you want her to try a .38, please start her out with a little heavier one and work her into the airweights.
Depending on how she does at the range, if she decides she wants to carry a .22 please let her!!! Like you said: at least it's better than nothing! She will practice with it because it's fun to shoot and I'll guarentee in the near future she'll be ready to move up in size! .22's kill people!! I get news clips from friends about this once in awhile (last one a couple of months ago in Duluth Georgia of a guy broke into her apartment, dragged her out of the shower and tried to rape her, would've love to see the look on his face when she pulled her .22 out from her pillow and started to fire-no he did not survive 9rds center of mass)
Yes, there is also the argument of rimfire carts having a higher misfire ratio than centerfire, but in weak or inexperience hands, chances are they are going to let that gun jump in their hands when fired and can easily get a stovepipe or other malfunction-therefore only getting 1 or 2 shots off!
I run Ladies Only Basic and Permit to Carry classes @ Bill's.
I know Tom T and would also recommend him 100%
Good Luck!!!
LT