Did you feed her or did she drink a lot of water before you went to the vet? Sometimes things like that make a big difference in their weigh ins when they go to the vet. :] Its happened plenty of times with Lilo where she just decides to drink a ton of water before we go and she gains an extra few ounces. LOLThey're so small so things like this can make a difference.
If not that, I know a lot of puppies have early or late growth spurst.
some will just continue to get bigger, while others get to a certain size then slow down a lot. Either way if Meesha's 10 pounds or 3 pounds she's still a cutie!