Besides what everyone else said, how about having your wife take your dog for an on-leash walk. Make it your wife's special thing and reward your dog when it goes pee and poo. Our dog is 2 1/2 and we still say, "good girl" or good pee or good poo, when she goes on our walks.
Also, is your wife just not paying attention to your pup when you are gone?
FYI, with our current dog and previous dog, neither could hold their bladder or bowels at 3 months old all night. I think I woke up to let our dog outside in the middle of the night every night until she got to be about 7 months old. There were times with our previous dog, a GSD mix, even as an adult I would occasionally have to let her out in the middle of the night.