I was watching my cousin's 8yo after school a little while ago and she (the child) asked me to supervise her while she had a shower. I was in the middle of something and said I couldn't but showed her where everything in the bathroom was, gave her a towel, and she had a shower.
My cousin, when she picked her up, was a bit miffed to hear this as she still bathes her. Admitted this cousin does like to keep her kids close to her - her daughter still shares her bedroom and her older daughter wasn't allowed to have her own room til she was 14 - but WIBU to think that 8 is old enough to shower alone?