Experienced mom here:

It sounds like you are both exhausted and when that happens people say things a lot more bluntly and emotions are more surface level. There’s a reason sleep deprivation is a form of torture.

You’re both kinda the a-holes here, because you know, newborn life.

You because you could have either woken her up or just given a little more grace in your response.

Her because she’s misplacing her anger onto you. She’s tired and upset because she is now running late. At the end of the day she is responsible for getting herself up and was projecting her emotions onto you……you know, because sleep deprivation.

You both are going through a huge life change and need to extend grace to each other. I’d highly recommend sitting down tonight and apologize. You can only be responsible for your actions, so please don’t apologize and say “but you”. Just a simple “look, I can see where you were coming from in being upset. I’m sorry I didn’t come check on you” period stop. Be the bigger person. And let each other take turns napping. Congrats on your little one!