A couple of weeks ago when my Gabby went to the vets she was 11kg at the time she was coming up to 8 months, the vet didn't say nothing about her weight She is that bit taller then my Jasper and a couple of inches longer (Jasper changes from just under 8kg to just over 8kg) and she is defo bigger boned then him, so I guess this is the reason she is that much heavier (I think she is slim enough).
So if Poppy is that bit taller and longer then average and you say she is bigger boned perhaps this is the reason she is this weight.
Also my vet surgery offers free nurse health checks where my dogs weight is checked and noted on their computer file and the nurse seems very clued up to give advice, I hope that if your vet surgery offers this maybe the nurse could advise you to give you peace of mind.
My two likes raw carrots as a treat. Good luck.
Jasper tri 21/Dec/05, Gabby ruby girl 8/Nov/07, and Felix the cat 4/April/10