My daughter has just turned 12 months old and is still not sitting up on her own </3 I have spoken to the health visitor and she has said this is because my daughters head is slightly larger than " normal" for Babies ( due to a health condition - NF1) and it's affecting her balance and that when she " grows into her head" ( not the exact words the Heath visitor used) she will be able to focus on balancing and I shouldn't worry.. But I am! Has anyone been through this before? AIBU to get a second opinion?