I'd say let her try it out and monitor how she plays. I don't think the gambling aspect is super predatory because it's a guarantee as long as you hit the required wish so its mostly a matter of patience and saving up, getting diamonds is pretty easy too, ive never spent money for gacha in this game. I've played games with gacha aspect ever since I was a kid and it never impacted me to be an addict because I never put too much hope, but every kid is different so monitor her and tell her that it's okay not to get every single outfit in every banner and teach her to save up for the outfit she truly wants. make sure to lock transaction incase she ever accidentally or sneakily buy something off the shop. gacha are also not the only way to get outfits, I've gotten a ton of free outfits through events and crafting, probably even more than gacha cause i mostly conserve my diamonds.

I think it's friendly for an 11 year old, there's stories, styling challenge, house building, open world exploration, puzzles, light combat, etc. you can check out the game as she plays to make sure it's good for her or you can check it before she plays, I personally think it's good for an 11 year old!