i think Liam was able to do it at around 5 months - that's when he was sitting unassisted. He hated the sling before that, so it was great for me! I don't think Rhiannon was able to do it until 8 or 9 months, because she took a lot longer to be able to sit, even assisted. She never really got good at it, because she had this habit of stretching her legs down straight instead of sitting on my hip. neither one ever liked the forward facing carry (i assume that's what you mean by buddha). until she could do the hip carry, when she wanted to face out, I had to use the Baby Bjorn instead.