YY: first, on a Ruger design semi-auto 22, the amount of "slide" that goes back and forth is fairly small, therefore it needs a hefty spring.
The Buckmark has a much bigger slide, and therefore since it's mass is higher, it uses a much lighter recoil spring (in other words, recoil is being controlled more by the slide mass than the spring). S&W also used to make a full-size "target" 22 semi and it's slide spring was so light, you could rack it by sweeping the slide on your pants leg. The Buckmark isn't quite like that but it's close, you'll find it is VERY easy for those with weak hands to operate. The Buckmark has a grip size somewhere in between the classic Ruger Mark2 and the Ruger 22/45 variant (22 caliber, but with a grip shape and controls that are roughly 1911 size for use as a "trainer").
Upshot: if DA trigger pulls turn out to be a problem, try and rent a Browning Buckmark and see how she does. If the range doesn't have it for rent, they WILL have a Ruger - have her try that, and if it's OK 'cept for the racking then back in the shop have her rack a Buckmark (and see if it fits her hands).
If she CAN handle a DA trigger, then a heavier gun like the GP100 will handle recoil better. 38s in a GP100 will feel pretty mild; 38+P will be a bit more but probably still within controllability.
GP100s come with two different factory grips, a bigger one and a smaller one. The smaller is standard on *fixed sight* GP100s, while the bigger grip is found on adjustable-sight guns. But swapping is only about a $30 thing, if you want to get an adjustable-sight gun and swap to the smaller grip. The smaller grip is about the size of the SP101 grip, maybe a hair bigger but not much. However, "trigger reach" on a GP100 small-grip gun will be just a bit longer than on an SP101 due to the larger frame size so if you're going to do the GP100 small-grip thing, it's critical that you have her actually test that combo for fit, even if it means searching for a factory fixed-sight gun at multiple shops (since they're not quite as popular).
Good luck. I really hope a DA wheelie does work for you both, but don't try and MAKE it work if it really can't, OK?
'Cuz priority one is that she be able to defend herself...and a Buckmark or whatever can do that.