I co slept with a newborn and a four year old. The key is to have a big enough bed. We had a queen with a twin next to it. My four year old was excited about his baby brother sleeping with us and daddy. It went baby, me, older son, husband. By a couple weeks old, I would sometimes sleep me, baby, older son, husband. But I kept my around baby. By a couple months old, I didn't worry at all about who slept where.