A yorkie girl will probably bond better to a male owner and a yorkie boy will bond better to a female owner. Thats what I see and hear when reading threads. I have 2 boys, they are brothers from the same litter, same parents. One is 5.5lbs and has the shortest little legs and body, he is compact. The other is long and lean and weighs in around 10lbs! The small guy was the largest one in the litter and when I took them home at 9 weeks he was bigger than his brother! You just never know what you'll get.
Also my vet did their shots at 15 months old and they weighed 6.2lbs and 4.4lbs. At 18 months they had a growth spurt and ended up weighing 9.5lbs and 5.5lbs. So again you just never know when they are done growing and how big they will be.
I think 6 - 7lbs is a perfect size for a pup, not too small where you worry constantly but still small enough to carry around without breaking your arm off!
