She has to want to quit, and perhaps the flavors she thought she wanted were not actually the flavors she actually wants.
My fiancée was sure she wanted menthol tobacco. After sitting down and trying a bunch of stuff at a vape shop, it turns out that she prefers slightly sweet, fruity ejuices. She does not like overly sweet fruits, chocolates, coffees, bakery flavors, or tobaccos for her ejuice.
What starter kits did you get her, Hitt? I got my girl a ProVari Classic (since the specials of the week are $50 right now) and a Kabuki Clone ($14 from FastTech, and uses Nautilus Aspire coils) to get her going. It's actually a better setup than my own, to be honest.