sunmeetssky answered your question:The more I think about it, the more worried I get...
John is married quite a lot in the original stories (not sure about a child though) but the writers will make it work, they always do…
As far as I know canon!Watson never had any kids. As for Mary in the canon? She gets kinda... swept under a rug after they get married, if that makes sense? So yeah. The biggest difference is the child and Mary in the BBC!verse being made into a much more important, integral character not just someone in the background. But I do have faith that they'll make it work somehow. :) Like you said, they always do...












