I'm also pretty easy to invent: Over the years, several people have clearly been playing to (sometimes unflattering) versions of an Ellen-Shaped-Object, which is not very pleasant, I can tell you!
Unless you are TRICKSTER!!!
Which I AM NOT -- BUT JESSICA CAMPION IS!!!!
This insight brought to you by a person I know who keeps trying to manipulate a (fairly nice, for once) version of me who does not, in fact, exist - and it is utterly hilarious to watch them try.
So if you were Jessica at age 15, of course you would figure this out, and create different versions of yourself for all the people in your world, and then watch them try to manipulate that construct - while you stand off to the side, laughing your fool head off and then doing exactly what you like.
Wow. I'd sure rather write about her than be her legal guardian - poor Katherine!