Ruger LCP + Crimson Trace
Kahr PM40
Walther PPS 9mm
Walther PPS .40
I'm hesitant to recommend the Kahr PM40 due to the nightmare this gun has been for me, but it's the perfect form factor and caliber for primary pocket or deep concealment carry (if you get lucky with one that works). I own both the 9mm and .40 versions of the Walther PPS, and those two happen to be my favorites since they are top quality, a pleasure to shoot at the range, very accurate (or more precisely, I'm accurate with them), and they are easy to conceal. They are only barely pocketable if you use a flush magazine. The +1 and +2 that they ship with are not very pocket friendly. So if the LCP is too small or has too long and heavy of a trigger, or if .380 isn't 'enough', do consider the PPS. I don't think she will be disappointed.
For ladies and guys both, I highly recommend the SmartCarry holster for any of the above guns. It's probably more ideal than purse carry since there's less of a chance of theft, and it works well with most single-stack sub-compact and pocket sized guns. It's also surprisingly comfortable.