P.B.
I think at seven they are capable of understanding but are still a little self centered at times. My seven year old was moody and mean to her sister until I realized that she was jealous of my little one being home with me during the day whle she was at school. My husband works a lot of nights so taking her out really wasn't a good option. Instead once a week I let her stay up late after her sister has gone to bed and we do different things together like bake cookies, play games, watch a movie etc. She feels like she is getting something extra and I always get a big hug at bedtime that night.