Hi everyone thanks for all your comments! 
They are not brother and sister. They are from different breeders. I love dogs especially Yorkies I've waited 10 years to get my babies. I waited till I was working part time so I would be able to care for them. Regarding why I want to breed - I only would like to breed them twice and it's not for any specific reason. I already have 4 very close friends who will provide pups with a very good home. But not sure yet I just might neuter/spay tehm. I just spoke with one of the persons in charge and he actually told me that the area I live in is not part of ordinance, animal control sent me letter by mistake I missed it by a block LOL .
The only problem now is that I still have 4 dogs and the city of covina will not give out a kennel license in my area.  
 
 