We had extended family here for nearly a week this Christmas. It was my husband's brother's family, which includes three children of the same ages as our oldest three children. We all had a great time! Cousins tend to play well together, I've noticed; I think there must be some genetic compatibility that is reinforced by the cousins having parents who were brought up similarly.
Sometimes my children, like any normal American child, express a little sorrow at not being able to have some material luxury, and I tell them that instead of giving them those extra luxuries, we gave them their siblings. When they are all grown up and their toys are ruined and forgotten, they will have each other. Siblings know where you came from, and if you have enough of them, you're (almost) guaranteed to always be on good terms with at least one of them. In a land of convenient friendships and an age where marriages too often don't last, my children will always have their sisters to care for and to be loved by. I can't imagine any ballet classes or My Little Pony collections that could outweigh that future blessing. And some day they'll bring their children together and get to enjoy watching the next generation of cousins play happily together.