That's awful. It must of been so scary for all of you.
I agree with Bec, there's a difference in being told not to cry because the carer can't 'bear it' and not crying because of her physical health. I think you are being completely reasonable.
Maybe to get some of the feelings out she could try journalling, get it all out, and only re-read it in a couple of days when she can cry if she so feels?