Hi Mwel I think that Just_me has a point but you still need time to process this yourself. Maybe you could reply back with.
I am not sure how long it will take me to process everything that has come about. I need time to work through all of this and my own feelings as well.
Or at least something to this effect. She has to understand that you need time. How long did she think about all of this before she even clued you in that she was unhappy or leaving. Hopefully she will understand this.