Hello and Welcome!
Labs are people dogs, they love being with their family and should be inside dogs. I'm sure others will comment on that.
We home senior labs, some who lived in kennel situations. From Potion who was 9, Melody who was 10, Bandit who was 7, Mardi who is 8, and Archie (who lived in not a very nice situation) who is 5 (the ages stated where when they joined our family), they all were very easy to housetrain. I use puppy training 101. Watch them carefully, outside frequently and super praise when they go outside. We make it a potty party. Unlike puppies, they do have the muscle capacity to hold it. They just need to be taught where it is appropriate to go-outside. Remember, your pup is used to when she needs to go, she goes. With your help, she can modify that. Watch for signs, circling, sniffing, squatting.
I remember the first day with Melody. She was in the kitchen and started to squat. I just told her, Melody lets out outside, and she did her thing outside. All of them have trained within days to at the most a week. Crating was important at night. Up early in the morning and straight outside. Always a positive experience, never scolding or they might trying to hide and go inside. Labs want nothing better than to please and Teal will catch on fast.
Can you put a crate in your son's room close to his bed?