As seen in Avengers: Infinity War, we learned that both Pepper Potts and Tony Stark were planning their wedding before Thanos had attacked, and it also seemed like Tony made it very clear that he wanted a baby. Now, bear in mind that both Infinity War and Avengers 4 were shot back-to-back, and Paltrow did an interview with a magazine, and here is what she had to say:
“Pepper and Tony have had a real long journey together. She obviously starts as his dutiful assistant, and then the relationship evolves, and now this decade later they’re married, and they have a child. Their relationship has evolved in all of the ways that great romances evolve.”
Now it’s hard to say what she is referring to, but we do know that Iron Man’s story arc will be wrapping up in Avengers 4, and for him to have a happy marriage, have children, and retire from the superhero life would be nice to see.
Source: Comic Book Movie