Good exercises for shaping the @ss

I have a ladyfriend who wants me to train her and one of her goals is to make her ass rounder and more shapely. She will be training at home with a pair of adjustable dumbbells, so no machines will be available for usage, only adjustable dumbbells.
Here's my tentative plan:
1. Lunges of some kind, but not sure which kind? walking lunges aren't an alternative in this case, as I live in a tiny flat.
2. Stiff-leg Deads of some kind, not sure how wide to have her place her feet? Standard narrow stance, or wide stance?
These are the 2 main exercises that I have planned for her, but any ideas or suggestions would be greatly welcomed. Thanks fellas
