Harry was born at 38 weeks, approx. 8 hr labour and he weighed 7lb 9oz.
Grace was born at 40 weeks exactly, approx. 2 hr labour and she weighed 7lb 10oz.

As Harry was born 2 weeks early I am sure he would have been an 8 pounder had he been born at 40+ weeks. So in my case my second was actually smaller. I don't know if the fact that she was a girl has anything to do with it.