If you look over threads we've had on "what gun for the wife" you'll see that you can't make that choice for her and shouldn't try nor should she let anyone select the caliber for her.
A gun that properly fits the individual shooter, regardless of gender, will not feel as if it has as much recoil as one that doesn't fit the shooter (yes, guns do, and don't, fit individuals). A gun that properly fits the individual shooter is quicker to learn with as it points more naturally for that individual and is therefore more accurate for them than one that doesn't fit them.
I've trained several people to shoot and many of them have been women. We always start off finding what fits the individual and then proceed from there. The experience is more fun and the individual manages the recoil better and is more accurate when the gun fits (try playing golf with clubs that don't "fit").
How do you know what fits? The two of you should look at
CorneredCat.com and read the "Trying on a handgun" section. The only thing I'd add to what Kathy is saying is that grip angle for a 1911 is different than one for a CZ75 which is different than for a Glock. Find the grip angle that fits the shooter and you'll be able to find the firearm that points most naturally and manages recoil best for that person. The "trick" I use is to have a selection of handguns with different grip angles (not much use having 3 Glocks to try since they'd all have the same grip angle) and then have the beginning shooter properly grip each one and bring it close to the chest pointing in the direction of a small target 20-30 ft. away. They need to stare hard at the target for several seconds until it literally becomes their total focus. Sounds silly, but it's important. Once that target is their focus they then thrust the firearm "into" the target as if a steel rod were coming out of the barrel and they were jabbing it into the small target. It has to be a thrust and not a sweep up to position. When they've thrust to full extension they should then, and only then, look at the sights to see what their alignment is. Is the front sight high or low or are they well aligned on the target? They're holding the gun that has a grip angle that fits them if they don't have to lift or drop the front sight to align it with the rear. If not, try an entirely different family of handgun. 1911 not work, try a Glock; Glock no work, try a CZ; CZ not work, try a ... (you get the idea).
Don't let some gunstore counter clerk tell her that she needs a .32 revolver or a 10mm Delta without finding out what fits her. If she points a 1911 then try different calibers out on a range starting from low to large. Same for a Glock or a CZ or Beretta or perhaps a revolver or whatever fits her. A good rental case is a great help in this case.
I've had tiny women pick a widebody 1911 shooting .45 over a CZ or Glock shooting 9mm because we went to the trouble to find what fit first. I've had others pick a CZ in .40 after trying 1911s and Glocks and others pick Glocks in 10mm. If it fits it makes hits better for the new shooter.
After the critical part is over you can put pink grips on most guns and you can also pink duracoat any metal if a pink version of the properly fitting handgun in the comfortable caliber isn't out there.