>>36234Well there's your answer OP.
You can see the problem is cascading up from her feet. The arches have collapsed, causing her ankles to drop inwards, which we see in her knee. Big women often cannot get supportive shoes that fit their feet and don't have the activity to strengthen them otherwise.
The knee is also rotated outwards, probably from tight glutes, due to sitting with her legs spread for that belly all day.
So yes, they have collapsed and will continue to get worse. She can get orthotics in the shoes to relieve some collapse near term, stretch out her hips, and do some strengthening. Probably best in the water, since aggressively loading a knee at such mechanical disadvantage will only hasten wear.
This part of caring for your ssbbw. Encouraging self care to make them as comfortable as possible, mitigating the obvious trade offs of carrying a couple hundred extra pounds.