My son's been using a Thermarest ZLite for 5 years and says he's perfectly comfortable, even on really hard/rocky ground. Our trips are typically 4-6 days. He's now 14, weighs 100lb, and I recently bought him a NeoAir XLite.
Imo, I wouldn't get her a heavy inflatable over a light CCF pad. The woman's prolite suggestion is a good one -- I used one just until last year myself. They're easy to inflate (MUCH easier, imo, than the air mattresses), warm and comfortable. For lighter people, I think it's more comfortable than the NeoAir types.