As soon as I saw their faces I knew they were pups.
They seem to be very sweet pups with good temperaments. Their good temperaments are another reason to believe they are either a Lab or Golden mix. Except for the Chesapeake, retrievers usually have excellent temperaments.
I don't recall if you mentioned whether they are male and female. If male, you should easily be able to see if they have been neutered already. A vet could tell you if a female has been. Either way, getting them neutered soon would be a good idea since dogs typically reach sexual maturity around 9 months of age. Neutering them before they reach sexual maturity helps to prevent some temperament and other problems caused by the mating urge.