A 7 month old yorkie weighs about what - 2 pounds? That is way to small to have puppies.
For several years when I was a child my mom raised and showed pomeranians. She bred 4 litters in 6 years and we lost more puppies then survived. And our bitches were older and had experience. We even lost a bitch in labor.
As someone who is experienced with delivering litters of puppies - in both small and large breed dogs - the advice given is the best thing both for your particular girl and for the breed. While it may sound very harsh (and not what you wanted to hear), would you make your 6 year old daughter have a baby?