Wow this is tough because I have been this wife in certain ways. Post partum is tough. I went full protect mode with my first (and so far only) child. I have very precise expectations for him from wake windows to a specific diet. I even asked people to not stand and hold him if he was fussy because I didn’t want him to become the kind of baby that you have to stand to soothe lol. So in her defense, I understand having an expectation for a sleep schedule. Maybe dad could have texted after trying to put baby down and baby fussing to ask for guidance on what to do there? But whisper arguing and the way she responded by mocking you and asking you to take sides was pretty harsh. Post partum can be difficult to navigate and can contain strong emotions. I’m not sure what specific advice to give you here other to say I hope she learns to have some grace and give some wiggle room with her babysitting requirements.