If anyone can point me towards things that seem to support Amber's narc version of events I would appreciate it.
The thing you gotta bear in mind here is not only is AL an enormous, narcissistic liar, but she controls (albeit haphazardly) the information we have to work with. We don't have a lot of other sources to ask for details. There isn't much you'll find to support AL's lies (since they're lies) but you're not guaranteed to find anything that proves an alternate narrative.
So, it basically comes down to a probability game.
Which is more likely? That all these breakups were more-or-less mutual, or that the adults in the situation (parents and so on) eventually told AL to get off their couch? With the possible exception of Destiny, AL can see the writing on the wall and make arrangements for the day when she's told in no uncertain terms that she's no longer welcome. (If anything, she's convinced she has the girlfriends under her control, but their parents always seem to outfox her with their superior grown-up brains. It must've been a terrible shock for the poor dear when Destiny managed to emulate an adult for five minutes and realize AL was a loser.) AL isn't just gluttonous; she's slothful. There's no way she'd "move on" unless she was sure she was about to be shown the door.
Consider:
She was living with her grandmother (and possibly her aunt, I forget exactly) in Oklahoma. It was obviously a huge shitshow, so she hopped online to find someone who'd feel sorry for her. Enter Kasey. AL went to visit "just for a month," and whoops! Grandma says she's not allowed back on the homestead in Oklahoma. Guess she's gonna have to crash at Kasey's place for a bit.
Obviously, this was a complete nightmare for everyone involved. Kasey's mom was already making unreasonable demands, such as AL get a job (shock horror). So she trawled around for another mark. By the time she and Kasey were ready to be "just friends" (aka, Kasey's mom was fully prepared to evict AL via trebuchet, if necessary) she had a new family all nicely lined up.
The only improbable thing is that she keeps finding people to take her in -- but when you think about it, the adults haven't been fooled. I think Krystle's parents were just really nice people (and maybe a little naive) and AL made sure to punish them for that by taking full advantage -- but even they tried to enforce expectations and eventually turfed her out when it became clear she was just a bum.
Oh man, Albert is the worst. What a lazy leech.
The best part is when she's telling the story, she says something to the effect of, "Kasey's mom was pissed, because she knew that she'd have to take me on" meaning "take responsibility for the 20 year old, 450 lb shrieking beanbag because god knows that's how the world works". She really saw Kasey's family as her next foster family -- just a bunch of people who had to feed her.
Edit:
@Malibougie said pretty much the same thing. Credit where it's due.
