MAN i have no castmates to offer but I've been watching this show and yes... Kon...... I am so happy to see people playing from this aaahhh

tabularasa_rp might be a good fit for you! There's no age limits so younger characters are definitely allowed, and as a slow tagger myself I can attest to it being very friendly to backlogging with a decent mix of tagging speeds. There's an ad over here and the FAQ covers the mechanics better than I probably could, but tl;dr the setting is being built from the ground up using character's memories and bits of their homeworlds, lots of emphasis on characters having impact over the game's direction, mixed genre events. AC is 10 comments so it's pretty light. The game does have a small player cap, but there's a queue for new players that's always open (and right now we're below the cap anyway so).

The only issue is that there is a 1-month wait time on apping from new canons/canon material, so you would probably have to wait to be able app her if you are interested :( but it sounds like it might be what you're looking for and I know I'd love to see some Kemono Jihen chars around, so I figured it was at least worth mentioning!

EDIT: me looking at your icon and realizing wait... that's a manga panel... wait.... this show has a manga???? so actually i guess the above point doesn't matter and also i have to go binge a new manga so thanks for that

EITHER WAY gl in your gamehunting endeavours and I hope you find a good place for her!!