You do need to take her to the vet, as soon as possible. It is always a difficult birth when the male is larger than the female. Something has to be done. This probably will endanger her health.
If you are serious about breeding her you need GOOD breeding advice, plus veterinary advice, and you need money, patience, and willingness to become a responsible breeder.
There is no room for accidental pregnancies with dogs. There are already too many stray dogs, abandoned dogs, many who came into the world "accidentally" and whose owners didn't love them. Finding a "good home" for puppies is a difficult task, and they deserve nothing less than a forever home with people who will love them deeply.
You obviously already know she's in trouble! You need to get her to her Vet today.....If she is still in early pregnancy, the fetuses can be aborted during a Spay.....Otherwise, if she goes full term one of two things will happen.....She will either die during birthing or you will have to pay around $1200 for a C-section to save her AND her puppies.....
All of this was completely avoidable if she would have been spayed.....
If someone chooses not to spay/neuter their animals, they have to be vigilant when a female is opinion season! Yorkies, as many small breeds, can have problems whelping and require C sections and that will cost you. You had better consult a Vet fir advice as, if she is in whelp, possibly the litter can be aborted. Please get her spay!
If you're aware that dogs of her size have trouble carrying puppies, why on earth didn't you get her spayed??
Only a vet can help you in this situation, sorry.