Is this normal...............?

when my sister was 8/9 she used to go on youtube and watch r18 videos. i don't think this was just curiousity. she did this for a few days straight. maybe a week. she might have done this before as well im not too sure. probably not. i caught her and told her that she should focus on school work and this is not the right age for these things. and then i think she was ok. i also think she used to get by scenes on tv. she told me she feels like peeing when those scenes come on lol anyway is it normal to be this ual at a young age? or could there be something wrong? thanks