Maybe just go back and say 'about what?' and if she says the mediation date maybe say 'oh sorry, I thought that was a rhetorical question?' Or you could just ignore it. Why should you be helping to clarify something you don't want! Does she realise how much this is hurting you? Also you could say 'I really don't want to talk about it that's why I didn't respond. Just letting it all sink in'. This so hard isn't it!
I'm sure you will get clearer direction from one of the vets on here, I can barely deal with an Invitation from H to go to lunch with D on Saturday!!
Me - 47 H - 45 D-16 M - 6 years Separated - May 16
Don't leave me behind can't you see me I'm shining... (Years & Years - 'Shine')