Baby milestones

Im sure all ofbtou like me look to see ifbtoir baby is meeting their 6 mo milestones. Am i the onlyone that my 6 mo old doesnt seem she is hitting them? She sits up for a few seconds then falls to side or front. Not un assistant. She hates being on her tummy so she immediatltbrurns back on her back. Shes nit even trying ro crawls, life herself up, hold her bottle etc...she can lift arms to be picked up. She loves looking at books, playing peek a boo. Sits up pretty well. Hand and eye foordination6is perfect. Saying babab mama dadda. Anyone feel like their baby is laging behind?