^ Yh Natasha and Yelena literally can’t have kids, they have no reproductive organ(s) anymore.
Hulk can’t have children either I’m pretty sure, due to his radiated …
And personally, I don’t think Wanda can have kids either. I think the experiments that Hydra performed on her, on even the power from the infinity stone—or both; made her barren. I know she was “pregnant” in WandaVision, technically, but she didn’t get “pregnant” by any normal standards.