I am going to add how difficult it is with a third. My sister has two girls and a boy. The two girls are into gymnastics, dance and one in band and they all have CCD. The boy is into soccer. My sister and her husband need help (me and my other sister) to get them all where they have to be. You cannot have a car - you need a van because the older ones always want their friends to go places with them and there are fights in the back seat (this one is touching me!). Also, two gang up against one when fighting. Usually the middle and the youngest are against the oldest. They don't share - everyone wants their own stuff and no one else can touch it. When you go to amusement parks, mom always gets stuck with the little one while everyone else gets to go on the big rides. Also, three to put through college, three weddings and no retirement left for mom and dad. Also, with three, there is a better chance that one will come back home to live (with their own children)
My other sister has two girls, and her life is a lot calmer and saner that the one with three.