Phew! If it’s a lab, then here’s some advice I gave someone yesterday:
I'd want to see evidence of the following health tests for both parents and the below scores:
Elbows (0/0 - absolutely nothing above this)
Hips (Under 7, but I would accept under 10)
BVA/KC/ISDS - Unaffected
CNM tests (on both parents - it tests for possible muscle disorders and you do not want a pup who is affected by this). Should show as clear.
Also relevant eye tests etc.
Basically, I would want both parents fully health tested. Lots of breeders do not test for CNM, PRA or MCD - these are DNA tests which a lot of people are not bothered about. But if your pup is affected with the relevant genes, it can cause enormous difficulty - particularly for active dogs like labs.
Inbreeding coefficient (you can see this on the KC website) below the breed average.
With dogs like labs, there is rarely an excuse to have a IC above the breed average.
I'd want to know why she chose the sire she did, what happens to the bitch when she can't have anymore pups, how many other dogs she has, how many litters she breeds a year, whether she 'matches' a pup to you (or lets you chose), how many litters the bitch will have (personally, I think more than two is far too many) etc. etc.
What I would caution about is moving too quickly. It's great you've found a breeder, but deciding which breed is right for you should take months to decide. I know some Golden breeders that are vets, and I wouldn't buy a puppy from them for all the nukes in North Korea - and being registered means nothing (either KC or Council) because puppy farmers can be registered with both.
I'd also want to be thoroughly vetted by her because I'd want to know that she cared where her puppies were going - and wasn't selling them to the first person who made an offer.
Ultimately, picking a breeder and a puppy is about critical thinking and using your gut - don't take things at face value and assume because someone has X background, they're a good breeder 😊