Miguel O'Hara: Miles, being Spider-man is a sacrifice. You have a choice between saving one person and saving every world.
Miguel O'Hara: My name is Miguel O'Hara. I'm this dimension's one and only Spider-Man. At least I was. But I'm not like the others. I don't always like what I have to do. But I know I have to be the one to do it.
Miguel O'Hara: And don't get me started on Doctor Strange and that little nerd back on Earth-199999.
Gwen Stacy: Who's "Doctor Strange"? A guy with a name like that probably shouldn't be a medical doctor.
Hobie Brown: I don't believe in teams.
Miles Morales: Aren't you in a band?
Hobie Brown: I don't believe in consistency.
Miles Morales: Oh this guy's killing me.
Answer: Who's saying they got married first? They reconciled, she got pregnant at some point, and they got married whenever. Do we even know if they are married? Mayday could be as old as 7 months. She's crawling and seems to have basic motor functions like pulling her hat down, so she's likely at the older end of that scale. While she's big-ish, she's not talking or anything, so she can't be that old. Plenty of younger babies still have a lot of hair, plus we can't be 100% sure how his universe works, in terms of child development or indeed be sure that time passes at exactly the same rate as Miles'.
Okay, you made a fair point on the whole marriage thing.
Cody Fairless-Lee