I think her whole "Knocking occasionally is stalking her" thing might be related to her buddy system mentality. Basically if she's so afraid of people that she can't be out by herself she's probably also easily afraid by people trying to initiate dialogue or hanging out. You'd be shocked how paranoid/scared some people can get by having over protective or controlling parents growing up.

As for the vending machine? She might have meant that they were the closests she had to additional friends but in truth they were closer to acquaintances or something.

On a side note, I can relate to her a [i]bit[/i] better now. When I was in High School everyone thought I was Gay... High School's weird. :/
+Apparently she has similliar tastes, I'm also a Merlin and Sherlock fan. I can get though why others wouldn't like them.