Also insist the adopter gets them in a puppy class! A cross like that NEEDS to be in class where their owners will be taught how to care for their dog and how to properly communicate with them. Make sure you stress that they will get big, strong, and independant fast. Be willing to take them back should the adoption not work out, otherwise they will be placed in a shleter and most likely euthanized because they are so large and energetic. Even though you had no idea that they could breed (a dog can get pregnant as young as 4 months depending on the breed) you still have a lifelong responsibility to these puppies.