Imagine the last time you got all your clothes wet, like after riding a log jam ride at an amusement park or you got caught in a terrible downpour. Wet clothes are hard to get out of, especially when they are knits, like leggings. Imagine being 500 pounds and trying to get out of wet clothes. Imagine having Amber's legs and needing to get wet lycra/spandex/cotton blends off of them. It would have taken her forever to accomplish and would have needed a lot of room. Factor in how exhausting it is to do anything, even standing still, when as fat as Amber and that's why she sat in wet clothes for hours. There is also the grim possibility that she doesn't have anything else to wear.
She's teetering on the outer edges of basic human competence and she really is teetering. It's obvious what one little injury will do to her, or one bout of pneumonia. But just living without sickness or injury is winding down for her. Every ten additional pounds removes the capacity to do basic things, like shower, change clothes without assistance, sleep lying down, standing up long enough to wash a dish, get in and out of a car. Or remove her clothes when she gets wet.
I've been thinking back to Amber when she was with Dustin. She still dressed as well as she could, she put up a pretense of having interests, her hair was cleaner, her wardrobe varied though ridiculous at times. Dustin is a tubby little player but she is lively and enjoys life and had no intentions of ordering his life around feeding times. We had little hints of what was to come - I've always thought she quit her job because it was too hard for her to dress well each morning, delay eating until break times and was unable to use the office toilets - but Dustin went to movies, wanted to travel and do fun things, and was not content to drive Amber from one buffet to the next and sit alone in movies while Amber binged in the adjacent theater. Becky is such a lump and has let Amber run over her and Amber doesn't realize that having such a listless and compliant partner is why she is going to be immobile by this time next year, if it takes that long.