My little baby is 4 and a half months old now, and is trying so hard to sit up. He hasn't been very successful, but here is a compilation of his accomplishments. Unfortunately for him, he probably won't be reaching his physical milestones as quickly as some because he is so big. He's got more weight to throw around, and his head is somewhere on the gigantic scale. The positive thing is that he tries, and he is HAPPY!