Missy,
My wife is 5’4” and 110. She has may firearms but carries a S&W 642 and/or a KAHR PM9.
I recommend that you go to a gun store and find one that fits your hand and is comfortable for you.
There is a lot of folks that consider a .380 a minimum caliber, and I would agree and recommend a .38 special or 9mm, but get one you can shoot. A .22 you can hit with is better than a .45 you miss with. That being said, My wife also loves her full size .45 (and she has small hands, half the size of mine), but thinks it is too heavy to carry all day long.
In order of caliber preference (least effective to most)
.25 acp (a rock is more effective
.22 lr (better than most people give it credit for)
.32 ACP
.380 ACP
.38 Special
9 mm
.40 S&W
.45 ACP
.357 Mag
10 mm
Lots of others, but these are the major players.
Bottom line - get a gun that fits YOU, in a caliber that you can hit with. Larger caliber is better.
Thank you for the run down on caliber effectiveness. Last night at class I used a S & W .22 semi-auto and I was pleased that I was able to manage the slide easily on that one. My DH and I talked about going down to the gun range this week to rent a few different pistols to get a feel for what I prefer. Next week we will be using .38s in class.
I was pleased and surprised that there was a good ‘girl vibe’ to the class. The video we were shown had a woman home alone who decided to take a gun class as its subject. About twenty-six people in our class, four of whom were women (we were all there with our spouses). Instructors were great, all retired military or LEOs, and basically I had my own private shooting instructor when we went to the range. It was a fantastic experience.