I have a 12 week old golden retriever.  She weighs in at around 11 lbs.  Should I be concerned that she is not gaining enough?  I have a yellow lab that is 40 lbs. and he is 16 weeks old and is just huge.  Could someone please respond to this? 

Thanks

I would be concerned at a 16 week old Labrador weighing 40 lbs! He is possibly over half of his adult weight already!! All that weight on his hips is doing him no good at all.

Regards, John

Although they are both retriever breeds they will develop differently and at different speeds. Even within a breed you will not find two dogs which develop in the same way. Thinking about the weight on your lab puppy, are you sure it is not stealng the golden pups food? Perhaps the golden puppy is pickier over it's food and the lab is clearing up the left overs?
I would be concerned as John says at the weight your lab puppy is carrying.
If you are concerned why not get both the pups development checked by the vet.