Me: Good morning-I imagine that is going to be a big relief for you to get that finally taken care of, unfortunately though I can’t watch her during those hours tho. I think M hours may have changed for the better so you can ask her.
Wordy? I'd go with, "Sorry, I'm not available." or "Thanks for checking, I'm not available."
Maybe "I Imagine this is going to be a big relief.." was an attempt at validation? But note, she did not express any feelings, which is the entry point for validation.
"I think M hours may have changed for the better so you can ask her." - Sounds like you are trying to help her solve her problems, but you're no longer in that role.
