I couldn't help wondering what your definition of small is in PV'S.I'm being completely serious, so please retain your flames for starting your fireplace these chilly nights(g).
Have her read through the Provari forum. Let those folks talk her into it. If it doesn't work out for her, you'll get a good PV!
I believe there are some 320 Mah look alikes. I have the 510-X, this one is about a millimeter fatter than the ego 510 but the same length. With a 2.4 ohm carto it has an acceptable vape. I recently came across another in the same but I can't remember what it was.