Yeah.  All large people with mobility issues are just fat.  I have been fat all my life, and I was keeping up with my young children, homeschooling one of them, walking around at zoos and museums several times a week, substitute teaching in the schools.  Then, I broke my foot in a complicated medical mess, and 11 months later, got my other leg slammed into by a motorcycle running a red light and broken.  I was pretty much homebound for about two years, put on more weight, and have settled into a mobility scooter and a brace on the leg that has permanent damage.  If I wear pants, you don't see the brace.  I was stategizing my way out of a corner at a Children's Museum yesterday (wasn't at the "excuse me" point because I didn't know which way I was going) and people ganged up on me for being fat and on a scooter... get over yourselves!!  Very possible she has other issues than being "fat."