Frangible?
If this is for in the house, maybe one of the exotic frangible rounds would be worth considering, to prevent the rounds going all thru the house, so to speak. I don't know if there are other people in the house, but that could be a factor. Problem is, if we are talking about something like a Glaser, practice would be too expensive! Maybe the 135's some talk about would be a good compromise between penetration and effectiveness. I live alone, and load the 158 +p in a snub as it is proven effective even from a snub. Cheap enough in 50 rd. boxes for good practice sessions. Not really that bad to shoot, and does not shoot low from a steel frame snub. Good project for some research, I would say. I can't think any of the high grade defense loads from the good makers would be a bad choice, unless they were too hot to shoot for her. And I suppose in winter, the lighter bullets might not penetrate thru heavy clothing as well as a mid weight?