I’m sorry, I think this is an attempt to make excuses for behavior nearly everyone would understand was not appropriate. When someone tells you how they feel, you do not get to dismiss their feelings on the basis that they just had a child.
In any workplace in America, telling an employee she didn’t know her own mind because she had “baby brain” would be considered a violation of employment law.
It’s not nearly as commonly accepted to tell a woman that as you are making out in this thread. Even if Meghan simply read the situation wrong, it would have been appropriate to apologize when she realized the remark upset Catherine. Instead she got upset at being told she’d caused upset.
We all have versions of what we believe here, but this is one I have a hard time seeing excused and disregarded.