Feral children usually suffered terrible trauma and abuse. Often they were disabled even before being abandoned. It's hard to separate those issues from the mere lack of being taught language. There are deaf people who weren't taught sign language until later in life, and they turn out ok.

Also she arguably got some socialization from the monkeys. I mean that's probably very imperfect. But it's very different than the cases of kids being locked up in rooms with no contact to anything.