[Lorraine]

At nine weeks, a little over a lb is small but at nine weeks you can't really predict that well the size it will mature to. I would suspect no more than 3 lbs or even less.
Nine weeks is far too young to place in a new home especially one this tiny. So, now that you have her, you must make sure she is eating well especially before you go to bed so she has enough energy to get through the night. Watch for hypoglycemia (low blood sugar) as that can cause death quickly. If she suddenly staggers, c0llapses, or even goes into seizures, check the gums, they'll be gray or white. Rub some Corn syrup on the gums for fastest absorption. Make sure she is breathing until she come around, you can dissolve some syrup in water to give to drink. Nutrical to have on hand is the best but this will work if you don't have any. I would stock a tube of it to have on hand. Then feed protein, chicken is best.
I have two little girl pups now 8 months old. One is 2 1/2 lbs, the other is 3 1/4 lbs. This is the first time in 10 years of breeding I have had these undersized Yorkies. The mother and father are both almost 6 lbs. I wouldn't sell them or let them go to a new home as I had to be sure they were okay and not small due to health problems which is often the case. I have had blood tests, bile acid tests which you can't do until they are 6months old,for liver shunt and all came back normal. They've never had a hypoglycemia episode or much of any other problems except they didn't take their vacc's too well or wormings. Now, I would just do a half vacc's on ones this small.
So, I gave one to a friend of mine that has the great grandmother to these little ones and the other is going to a friend of mine that has two of my dogs. Yes, I gave them to them at no charge except they want to pay for the spay which is less than $200.
I gave them to them because these little undersized ones can be costly for Vet bills. If there is any signs of illness, vomiting, diahrea etc you have to get them into the Vet immediately as they are too small to have any reserve to recover much on their own. I never breed for this small and have no idea where these two came up this tiny from. My Yorkies are usually between 5 1/2 and 7 lbs.