Connie - If I were in your shoes I would sit her butt down and tell her exactly what you just said here. NO ONE Should have to feel like they need to sidestep and tippytoe around someone in their own home especially one who's bent over backwards.
You are a great grandma
I already know this .....and Maddie is so well behaved that I can't see her even being a problem around a baby especially if you're right there.
that girl is just being a drama queen to talk to her like that. I have to say I don't think I'd like her too much either. I LOVE my sons wife and can't imagine her acting like that. What does your son see in this moody girl I wonder ?? People who just had a baby should be on the moon ....
if she's in YOUR home - you need to set down some rules & let her know what you expect so you don't have to go 'find stuff to do' in your own house.