Chick gun owner here.
My husband is incredibly knowledgeable about guns. Owns dozens. He helped me shop, but I ultimately made the decision about what worked best for me. I also took a class in '01 where someone other than my better half taught me the basics of the gun, the law and how to shoot. I have a current carry permit, after taking the updated class since the law change.
I've seen so many nightmare situations play out at the range where I've seen husbands trying to teach their wives to shoot and a) they don't know enough to be teaching anything, and/or b) marital discord rears it's ugly head as one spouse acts like a jerk/belittles the other/or puts .40 in her hands and laughs when she gets knocked on her butt. Not cool.
Find someone who can work with your wife so she is comfortable handling the gun. I know someone in the Ames are that is a certified instructor and can work with you and/or her in group or individual scenario. PM me for contact info. Big time ISU connection.
I have a small hand. I have a Sig 239 9mm, Hogue grips. But, I don't like shooting a lot of rounds through it - makes my shoulder angry. So, a year ago I bought a Sig Mosquito .22 which is set up just like my 9mm,, but is much more comfortable for me to do a significant amount of target practice. Oh, and the skeeter is PINK.
While shopping I held MANY guns. The Glock was too bulky for my hand. The Sig was a nice fit. So, my suggestion is that make a date of gun shopping and have her get a feel for it and be able to say what make of gun is most comfortable for her.
While lots of people will give you advice about what is the best make and model, the reality is that you and your wife need to go and hold a lot of guns and decide what is best for YOU, not everyone else.