Breeding, and raising healthy well adjusted puppies, is certainly a serious business. While Yorkies are less likely to end up in the pound--less likely than lets say a pit bull--it doesn't change the fact that there are lots of pets out there, who are already out there, that need good homes. Your puppies may fill one of those homes that would have taken a rescue...
Just a thought.
Another thing to consider is, of course, whether of not you have the time to devote to the needs of several little ones, and also if you have the money to see them through their first few shots and check ups.
If you're only planning to use your pup as a sire, while someone else does the rest, I would first make sure that the female's family is planning to be responsible with the puppies as well.
My male, Theo, is not neutered. The reason for this is that he has so little personality already (haha) and I didn't want to risk it.
Do to this, though, he foams at the mouth and chatters his teeth when he passes a female--which can be embarrassing--and pulls and tugs on his leash.
It's up to you! If you choose to breed, just make sure that those pups go to forever homes. I don't know how I'd ever sell any of Theo's puppies... he's family. Good luck.