I mean, in theory she can go back to being a tanuki if she "wanted" to, so not exactly as real as anyone else.
Well I imagine that as time goes and she grows up she could almost completely forget about being anything else than a human in which case it'd be harder to reverse into a tanuki, maybe only knowing about it subconsciously. Then again the cat lady whose name I forgot clearly hasn't forgotten, so it's possible one can grow up while remembering just fine, and well if there was such a "danger" I think she would've mentioned it, well it could be a possibility instead of a certainty with different "false children" showing different results.
I'm curious as to what kind of situation could lead to her becoming a tanuki again further up growing or as an adult... maybe some trauma strong enough to make her not want to be herself/human anymore? maybe a situation where she'd wish she could run away from everything? it'd be interesting to see what are the implications of reaching adolescence since that'd be a point where she'd be particularly unstable.
I also wonder just how capable she'd be at "pretending" adolescence, I can get that she'd grow to adapt to her environment but that also suggests it depends on her perception of the environment and last time I checked some changes in adolescence ain't that obvious to a kid even if they teach you about them, like how mood and interests change. How quickly would she adapt to those changes? could she misunderstand and think of them as more inmediate changes and grow up quickly? not from one day to the other but reasonably quickly, or could she just miss on everything and just one day realize all of her friends have changed greatly in many obvious and not so obvious ways? maybe she just wouldn't change at all apart from physically growing at an average rate?
Well in any case the manga was cool, I'm acc happy this didn't become a 400 long sol comedy manga where nothing happens. Even if I'm curious about how a false child would grow up it's pretty clear to me that this is what the author wanted to make and I can't see this becoming a good hundred long manga.