Very late to the party, but I was reading through the thread and noticed there was some controversy about whether AL was a lesbian or not. I can't guess her sexuality, but could her interactions with people, possibly, be her reacting to that with which she is most familiar?
Coming up in the foster care system and being female, is it possible that she's had much more experience interacting with women like housemothers in her group homes? These people had authority over her and I would guess that learning to manipulate them was the way she learned to get by, so manipulating women was something she put some effort into. Coming from the foster care system, if you are not all about "me" then you probably get left in the dust. I'd guess there's not much about "giving back" (who would you even give it to) in the foster care community. It's more about taking what you can get.
Also, I would guess this occupation (sounds like a crappy, thankless job) doesn't require extensive education, and those are the type that she is most successful and comfortable with so she has continued to seek them out.
Being dependent and manipulative seems to have been her life since a very young age and seems to be all she knows. Granted, a more intelligent person would realize that it's on her now, but with her extreme weight (which she considers a disability) it sounds like she has convinced herself that she does not need to assume the responsibility for herself that an able-bodied person would be expected to assume.
Sorry for the extremely long post just to say that I'm not certain that sexuality has all that much to do with it for AL. She's just a damaged and not too introspective girl doing what she's always done to get by. Since it seems to be working for her -- I mean she has her living, enough cash for buffets and quick Walmart pick-me-ups, it would be surprising if anything changes.
AL is what she was taught to be and clearly doesn't have the brain power or the ambition to learn or accept a new path. I hope no one took this as a defense of AL. It was just a POV that occurred to me and I hadn't seen it expressed previously, but I could have just missed it.