Lemme see if I got the OP right. This will be a woman, unfamiliar with guns, and who wants something for personal and domesticated animal protection.
So, let me think of my wife as the woman in question. SHe could not handle a 12 gauge or even a 20 gauge at this point. A semi-auto would be a foolish choice - I either see her intimidated by it, or sinking to "spray and pray" techniques.
I hear the replies now: "She needs training!" No arguments. But we're talking farm hands here. Never in 20+ years of rural living and farm work have I heard of a farmer plunking down the dollars for a "tactical" gun let alone a training class. Most balked at having to have their sons take the state-madeated hunter's ed class.
No. She needs something light, easy to pack, and non-intimidating. My suggestions are along those lines.
I would select a 2-gun armament.
#1. The .410 "Snake Charmer" shotgun. See:
http://www.verney-carron.us/pages_us/iii_technical.htm. It's short, light, and fast to get into action. Used lots of those on farms for rat hunts and snake patrol in chicken coops. Loaded with #8s, it's deadly. Loaded heavier with #2s or even BBs, it'll take out "feral dogs" at close range when they were getting near the sheep pens. Load with slugs and you'll have a 50 yard gun, easy. Snake Charmer comes in 2 sizes; the shorter size has a hollow stock that allows 4 or 5 shells to rest in there - immediage back-up ammo. Put a simple sling on this gun, and she can sling it across her back and have it ready to rock and hardly notice its weight.
#2a. Ruger single six, 4 5/8 barrel, with .22 magnum cylinder (although the .22LR would be better than nothing). The .22 magnum is pretty decent as far as a small game fetcher, and while I personally would prefer a Ruger SP101 .357 on my belt, for a noob, I think this an excellent choice.
#2b. If a DA revolver would be preferred (some say DAs are better for noobs), then get the Taurus 94 (22LR) or 941 (22 mag). The inexpensive .22s (I consider the magnums inexpensive compared to centerfire) allow for her to shoot a lot and get comfortable with it, learn sight picture, trigger squeeze, etc., and become proficient enough to feel comfortable in its use.
Having spent a lot of years in the barns and fields, I can tell you that with "heavy" guns (Mossy 500s, .30-30s, and other long guns), they are the first things to be set down. In my pre-pistol days, I carried a Browning .22BL lever action - short, compact, and fast. But even that, when wrassling haybales out of the loft, I left it at the door. Never failed...that's when I met the snake hiding in the pocket between bales. Wish I had that pistol. She needs something light, yet manageable; moderately powerful, but not intimidating; something easy to learn and operate, yet sturdy. I think these two choices cover that. My $.02 cents worth. If this were my wife, these would be the two weapons of choice I would suggest for her.
Q