Honestly, the best thing to do is to take her to a gun store and/or better yet one that has an indoor gun range and rent some guns to see which one she likes best before she makes a purchase. That way she can see which one is most comfortable in her hand and if it's a semi-auto you need to be sure she can rack the slide without a problem as well as do a basic field strip. If the gun is too complicated for her to operate or it's not comfortable in her hand it's better you know that before she spends her money. Secondly, shoot the gun and make sure she is proficient enough with it so that she has confidence in it in the event she needs to use it.
Having said all that, my personal suggestion if you are dead set on a 9mm would be to check out the Sig Sauer P239 in either DAK or DA/SA. The 9mm round is no slouch as some would have you believe, especially if we are talking about some good quality SD ammo like a 147gr +P JHP.
Having said all that, my personal suggestion if you are dead set on a 9mm would be to check out the Sig Sauer P239 in either DAK or DA/SA. The 9mm round is no slouch as some would have you believe, especially if we are talking about some good quality SD ammo like a 147gr +P JHP.