Update
Mom still can't afford a new vacuum right now. She just vacuumed today, without me. So I'm still at a loss.
After exhaustive research, I've narrowed it down to one of two choices:
1. Bissell Cleanview with OnePass, 9595, $80
2. Hoover Windtunnel Air Steerable, UH72400, $160
Ugh. Once Mom gets a new vacuum, she will return the Dyson DC07 to my house.