Parenting: Elementary Ages Community

I have a 7.5 yr old girl. She is identified as gifted (started school 1 year early but reads 2+ grade levels above class).

This is not a new problem but now that she is more capable its becoming more difficult to deal with.

She is a perfect child - respectful, helpful, attentive, resourceful and pleasant - when she is away from home (school. church. camp, friends) but she is the complete opposite when she is home...not always but she is quite often unhelpful, disrespectful, inattentive and combative at home.

I recognize that some of this has to do with the fact that she gets away with stuff when she's not home. Her qualities make her a go-to student at school and other places but at home she has to pitch in, clean up, and share with her little sister. I recognize that we give her a lot of latitude b/c she is capable.

Her disregard for the rules at home is about to drive me crazy...example; if she wakes up bf the last adult wakes up she is not to turn on the TV...she woke up bc the last adult almost everyday and turned on the TV almost every day unless we unplugged it the night before. when asked why she gets sheepish and says she doesn't know why she did it and yes, she understands the rule.

A psychologist said that she doesn't have regard for the natural heirarchy within the family.

She has a 4.5 year old sister who is cooperative and respectful and aware enough to tell her big sister that she isn't doing what she was told and she's gonna get in trouble.

What can I do to help her understand the role she plays within the family?