definitely. i wonder how he existance came about exactly now ._. even though she's not a touhou char she's still pretty neat. she's definitely not in 12 as i'm playin it and she's not in 12.3 either right? I'm sure i saw the roster and she wasn't in it...unless she's a boss you can't play as or something lol. I doubt it though. highly.
I say both. She may be an original character, but she's an original touhou fancharacter. (Meimu should probably receive the "original" with her tags as well, by that logic.)