First of all just b/c you and your Sister got puppie's from the same Litter, does not mean all of the Puppies will be the same size. Yes, there are alot of Health Problems being over weight and she should not be "Free" feeding a puppy. A Dog will eat until there is no more food and will eat regardless if it's
hungry or not. I have scheduled feedings for my 3 Yorkie's. You should control every aspect of your Dogs life, that also includes "Feeding" it's Food and controlling the amount of Treats and Table Food (A definete NO NO!)
Exercise is very Important as well, even though Yorkie's are small they still
have to be walked at least twice a day, it helps keep them balanced along with keeping them Healthy/weight management.
My last Litter I had 3, 1 male and he is 7 lbs. 1 female was 5 lbs. and I kept the runt. Tiffany Aloha is 4 1/2 lbs. and they are almost 2 yrs, old
Not all puppie's from the same Litter will grow at the same rate or have the exact genes. You pretty much can't say anything without her getting offended or taking it the wrong way? I have the same problem with my Sister that has 2 Yorkie's too! I could tell her anything but she can't handle any criticism about her Dogs w/c are like her Children. You should tell your Sister to join YorkieTalk and maybe she will learn on her own? Good Luck
