Input from Mummys with 2 boys and then a girl ....

[Eleanor ace]

For me:
Boy, 42 weeks, 9lbs 15oz
Girl, 41 weeks, 8lbs
Girl, 40+5, 8lbs 9oz

So mine didn't get heavier and my boy was the heaviest by a fair bit. I was my mums 3rd after 2 boys and was her smallest baby, my next brother weighed 2lbs more.

 

[Kay0102]

Seems like it's pot luck. I shall make sure I update when she's here! X

 

[Bellaloo12]

I can shed a bit of light i had
boy 6.15
Boy 6.3
Girl 5.7
All mine got smaller i doubt thats much help to you but hopefully this one is a girl and is smaller than your boys x