The reason people choose those loans is because they cannot afford the monthly payments on a regular straight-up mortgage. I.e., that's why I say she never could afford it.
Also note when she purchased the house: 2005. I.e., she likely paid top $ for it and now it's value (after the housing crash) has substantially fallen. But this is a near universal problem, not one particular to her specific circumstances. IMO, she needs to move on from the house thingy as she has other, more pressing problems.
In any event, I'm willing to bet she can stay in that house for quite some time. People in many areas are pushing off foreclosure for extended periods and consequently remaining in their homes without paying for up to a few years.
She's unemployed, with a house almost certainly underwater and facing huge medical bills. I understand the desire for a parent to leave something to the kids, but under these circumstances that's an impossibility. In fact, without her medical problems it's currently still an impossibility.
Fern