To start, never underestimate what someone can handle, my cousin is all of 5' and maybe weighs 100lbs wet!, she loves shooting my .44mag, my wife is 5'6" weighs in around 115 and shoots the crap out of her .38 snubnose with +Ps. The best advice I could give you is to let her shoot what ever she can and decide whats best for her, the most important thing to remember is, if its for personal protection, it needs to be the easiest thing for her to operate under stressfull conditions, thats were wheel guns really shine!.