HELLO!! Fandom AUs are case by case! In your case I'd likely allow it depending on your app/samples cuz I don't think there are people out there LINING UP to app canon Hey Arnold! characters lol. It's also less of an AU and just more interpretation of [helga a few years later]

THAT SAID what matters to me more is the player!! So if you do app please identify yourself clearly cuz we all know cartoon players be getting reps up here sometimes. Thank you!!