Whatever you do, please look into taking the guns for a test drive by borrowing or renting them before buying. Most people do NOT like the recoil of a lightweight .38, such as my S&W 642. Yet they seem to be the most oftenly purchased gun for women, perhaps because many guys look at the cute, lightweight little gun and think "lady's gun". Especially the ones with the pink rubber grips. My sister, for example, doesn't like the recoil of my 642 one bit. She much prefers her 4" 681 shooting .38 +P, so she is considering a 2.25" Ruger SP101 for her carry gun.
She might well like it fine, I work with a lady who carries a titanium frame Taurus .38 and finds the recoil to be tolerable.
So let her try some different guns out, revolvers and autos, having her pay particular attention to how the gun feels in her hand.