She is not abused, she was a phenomenal child actress

"One moment Thivisol is romping playfully on the set, less than a minute later she is highly concentrated and embodies very convincingly the role of the girl who has to learn to cope with the recent death of her mother, while she doesn’t understand the concept of death."

There is a documentary about the making of the film with the actress.
https://iffr.com/en/2012/films/jouer-ponette