Once upon a time, I gave Cammie a sister. Specifically, an Australian redback spider (their variant of a black widow.) And the running gag with her side of the family is that they're all named after alcohol (whereas Cammie's side is usually named after tea)

So her name was Foster, and had a sun-spider husband named Lager. I think I only ever drew her once, so it wasn't a real prominent part of the lore. But I still think about her now and then, usually as a rival that Cammie can't stand. She has no children, no class, a condescending attitude, and her mate is still alive. Mostly because he's a tough son of a bitch.

That's all mostly the same here, but this time they're just not related. They're "Friends" from highschool ("Friend" meaning that they were constant rivals with one another and chided each other at every chance.)
But whereas Cammie has grown up and moved on a little? Foster just kept riding that ego and keeps it up into her adult life. Making her... pretty unpleasant company to say the least.