when my younger sister was 9 she got a phone, and because she had no internet restrictions, she very quickly found out about porn.
i saw some of her porn drawings in her notebook, and i found searches for porn in her search history. during that period, she was much more unhappy and also would force our younger, 7yo twin siblings to touch each others' privates and would be incredibly inappropriate. since her phone was taken away and her access to porn, she's gotten much better and has stopped the 'weird acts'.