Well, a few hours after my last update Mum and Dad made it up here to pick up Megan and take her back home. She said she's fine, but something's still off about her. Well, understandable really since she's been missing for a week.
Honestly, we still have no idea what the hell just happened. I'm thinking maybe she accidentally ingested some really funky sort of drug and caught a taxi or something up here, and then just wandered around town for however many days before getting into my house with the spare key she knows I hide outside. If she was drugged that could also explain the memory loss, and if she's been out in the sun for days that would probably be why she's got that burn on her arm.
So, yeah. Everything's relatively back to normal; all family members are accounted for, and work still sucks.