Willow is 5 months old, I had her weighed at 4.5 months and she was 6.6 kgs. I thought she was quite skinny, and like Ralph very leggy, but the vet is very happy with her and said whats more important is to follow a steady "line" on her weight chart - he said hers was perfect. They all mature at different rates, Poppy is 4.5 years old and weighs 11kgs - but I think she looks a bit weighty at the moment. I think how they look is more a better guide - you know your own dog best.