This board is mostly pet people and not breeders. Those of us who show/trial and/or breed, who are on the board are generally in favor of responsible breeding. For the best outcome for you and the owner of the dam, I would suggest you try to find a mentor or two in the local Labrador clubs. Puget Sound Labrador Retriever Association is a great club in your area:
https://www.pslra.org/. If you don’t have a mentor in the breed, you might look into whether a repro vet is local to you to assist. A lot of dogs are not actually bred under live cover now. Like people, dogs can get sexually transmitted diseases which can lead to sterility for the male and problems with the pregnancy for the female.
Breeding responsibly is not for the faint of heart. There’s really no excuse in this day and age to not get all the clearances recommended by the parent club for the breed on both the sire and dam. Hips and elbows should be graded with passing grades/normal by OFA, TVD is a known heart issue for Labs, and while our understanding of the disorder’s mode of inheritance is not complete, clear echocardiograms for both dam and sire are what we are looking for to try and curtail this issue; your dogs should have an ACVO eye exam yearly; have they both been cleared for EIC, prcd-PRA? These are the health tests the parent club is recommending:
Canine Health Information Center: CHIC Information. There are other tests out there that rule out issues like HNPK, which generally is not serious, but I wouldn’t want to produce affected puppies that will mostly get placed in pet homes with people who will have to manage that condition.
Ultimately, there are a lot of Labradors bred each year. Most, unfortunately, are not bred to any standard or for any purpose — just a bunch of generic black/yellow/brown short-coated, long tailed, drop-eared dogs. If you and the dam’s owner really feel like your dogs are worthy of being bred, please at least do the necessary health clearances.