My LO is a bigger baby 99% in height and weight. Our pedi said that his development may be slower because he so much more weight to hold up. He is no where near to sitting unassisted. He rolls everywhere as his movement. My mom tells me to enjoy it and I am trying but I just wish he could sit up. We are still bathing him in his newborn tub and he is getting to big, we tried sitting him up but he just fell over to the side. Anyone else go through this?