Thanks for your thoughts!
Actually, the breeder's lines are working retrievers - long, lean-legged dogs. He doesn't do much with show stock although he did so back in the 70's - he doesn't like the heavy-boned, heavy-coated show lines now. His dogs are bred to standard, though, but his primary emphasis in on intelligence and temperment. I have to say she is extremely smart. I've had 10 dogs over the years and so far, she may be the smartest I've owned.
The first golden I owned with 1/2 field (mother) and 1/2 show (father), but she took after the field line - lanky and an absolutely stunning copper color - even had drivers and cyclists yell out "Stunning dog" as they drove past when we walked. She was over-sized, though, but since I don't show, I didn't care.
The second golden I have now is also 1/2 working (mother)- 1/2 show (father), but her body build and energy level takes after her show father. She's very sweet, but when it comes to chasing rabbits, well, lets say her short legs provided the bunnies with comic relief.
If your breeder is a long-time, experienced hobbyist, then I'm going to assume that he or she tries to adhere pretty closely to the standard--for bitches, that's 21 1/2 to 22 1/2 inches--there's a one inch deviation either way, but the bitch should be proportionately penalized. Anything above or below that one inch deviation is a disqualifying fault--I have seen two goldens wicketed out of the ring before. It's not common, but it is done.
For dogs, the standard is 23 to 24 inches in height at the withers. Your "relatively small" 7 year old female is really not small at all--she's right within the standard, albeit at the low end, and she's also right within the weight range--within 55-65 lbs (dogs 65-75 lbs).
Breeders can't get "official" clearances from the Orthopedic Foundation until their breeding stock is at least 24 months--that's when you can be assured that growth plates have closed. You are really not going to know her "official" height until that age, and depending on the line she comes from--fast growing. . .slow maturing. .. for example, at this point, just enjoy her, and realize it is what it is--you don't want a golden that is outside the standard anyway--too much stress on joints and muscle and structure (IMHO).