Amirah-momma,
I certainly won't argue with the comment from your Vet, however...
The situation of overweight is not based on a given poundage, but, the condition of the specific animal. MANY of our Members have Dogs which are more than 7 lbs, and as I remember, the heaviest Yorkie ever, was just over 20 lbs.
Continue to heed the advice from your Vet, and as always, good diet, exercise, and a LOT of love, keeps our Fuzloves in the best of shape.