1) Diet advice is no soda drinks, processed foods.
2) If she is not getting enough movement during day, and not into martial arts, why you both don't enroll in dancing classes (at least twice a week)
3) Inexpensive equipment, jumping rope and resistance bands
4) Adjust exercises to match ability, like 15min a day, minimum 5 repetitions 2-3 sets at high intensity. Probably she can't do pushup but lets try leaning on wall or leaning on table or 2 chairs. Same with pullups 2 chairs and broom, so from floor try pulling up.
5) Jumping rope, burpes (if not possible with squat jumps and pushups do it without them), running upstairs
6) Don't expect fast results, take photograph now and compare it after 3 months
Books:
Ross Enamait Never Gymless
Wendie Pett Every Woman's Guide to Personal Power
-List of bodyweight exercises
http://www.fightingarts.com/ubbthreads/showflat.php/Cat/0/Number/15833023/an/0/page/0#15833023
-Some training videos
http://www.metacafe.com/channels/fitnessvip/
-Nice articles and videos
http://www.rosstraining.com/articles.html
- Self resistance exercises
http://www.angelfire.com/ny5/shenandoah/OBB/OBB.html
Note: these exercises require mind to be focused on exercise or it will not have desired effect
-Women's weight training
http://www.stumptuous.com/cms/stumptuousblog.php