Not to be size-ist but skinny babies do learn to walk sooner, even as young as 6 months. Its totally surreal to see a baby walking that young but it happens. Chubbier babies (which I find cuter - my bias!) take a little longer I think to find their balance. But so what? I don't think it really matters in terms of who is ahead. As the song says - its not where you start its where you finish. George walking early does not mean he will be exempt from his parents laziness.
My friend has the cutest little chubby baby and he just starting walking just shy of seven months. Never crawled - just went from sitting up to walking. Doesn't even hold onto furniture! It looks odd to see him as he is only 27 inches tall...but it is so adorable too! Plus he just smiles and smiles...so very proud of himself, he is.
Her pediatrician said that 9 to 15 is the usual age range but earlier happens for some. No worries for anyone unless the baby is 16 months and