We just had my daughter's 6 month visit (she was 6 months last weekend) and the doctor was a little concerned that she's not sitting independently yet. She can sit for a few seconds, but eventually flops over. The doctor wants to see us back in a month to recheck it. I didn't realize this was such a hard and fast 6 month thing. I've been trying to work on it with her but she just wants to roll everywhere - she doesn't stay still! Anyone else have a late sitter? Any tips to encourage her?