hello angel
i am much like your sister. plagued with ailments that impede weightloss and are responsible for weight gain.
my knees are injured and i have plantar faciarittis in my feet most likely from walking badly and limping with my crook knees. I also have osteo arthritis in my feet, another arthritis in my hands and some bizarre thing called fibromyalgia which i thought was just one of those weird things hippies got(joke)
anyhow this isnt about me, what i was trying to show you is that i came from being unable to walk to today, where i am out in the garden again laying pavers and lifting sleepers(on my own) which i wouldnt have beleived possible nearly a year ago.im slowly getting back to my pre injury and pre arthritis strength and im 40 yrs old.
for feet, dont mess with them, get her to see a podiatrist. its not something i would self diagnose as feet are very crucial to her fitness.podiatrists are better than docs too i have found, docs know a little of everything but not alot about most stuff .
for exercise with out feet pain i have just bought a bike as recomended by 3 specialists helping me mend. absolutely no foot pain on the bike. i have to do my calf exercises to walk though as directed by the podiatrist. for me, calf exercises are the difference between excruciating pain and inability to walk to mild bareable pain that wears off as i walk more. nothing worse than jumping out of bed to feel those humungous metal nails being pounded into your heels(well thats what it feels like)
a podiatrist will also check how your sis is walking and may have be able to help correct it.
anyhow, i have rambled enuff
good luck to you and your sister
heres to happier heels