The answer is to latch onto a Ruger MkII or MkIII. She will find the grip is smaller & a bit like a Luger. The women in our Club use them all the time & shoot well.
I would highly suggest the Model 678 which is also called "Target" for it has 6 1/4" tapered bbl BUT with adjustable sights. The front blade is perfect. The weight is a bit below the 5.5" Bull Bbl model 617.
One member brought one in this winter & we can see for a lighter but accurate semi-auto THIS 678 is THE answer.
Personally I would stay away from a fixed sight as she will have to Kentucky to get into the bull & that is discourging.
I think the 678 Target has only been out for a few yrs so in a possible 'used' Ruger you might run across one, but do not hesitate about the 678 as our Club women have been using them for some yrs.
Also cost of this gun is below many makes & if you look at a S&W Model 17 revolver, you are looking at 6" bbl with the underlug weight & while fine for us men it is a lot of weight for a woman & the K frame grip might be a bit to much not to mention the cost NEW is around $850.00 & I think a NEW MkIII 678 or 512 are identical, in price, which I think(?) is around $382.00 American so you figure out the cost in American dollars plus taxes.
One of my jobs is to try & advise people/members in what to buy along with how to shoot them, which is always a .22 & later a center fire, but in the latter that means reloading & so an additional cost in press, all the extras, bullet tips, brass, primers, poweder & such. Obviously good reason to start out with a .22.
After a season she will feel at home with decent grouping & that will give her a chance to try out center fire h/guns of others to possibly latch onto the center fire she can handle the best, but do not let go of the .22 as it will pay off some yrs down the road. Why anyone sells a GOOD .22 rim fire is beyond me though I have 9mm, 38 Spl, to two lovely custom made 45s & love the latter two, but always start the shooting day or evening off with a .22 be it one of my High Standards or the Ruger Mk II 512.