I think I missed most of this already, but thought I'd pop my head in to say sorry that your friend has upset you so much. I think, and I could be wrong, that from the tone of her eMail and everything that she sounds like she is just all wrapped up in her own stresses and didn't like being criticised for anything. I think there are some people who just can't handle any sort of criticism and get all defensive without really considering anyone else's side.
If I were you, I wouldn't keep writing her back and forth about it. In her response to you, it sounds like she doesn't want to get into it and just doesn't think she's done anything in error and if that's the case, you won't be able to convince her otherewise. I would just let sleeping dogs lie, before you let yourself get wrapped up in it. It is probably upsetting you more than her.
Hope you are feeling better about the whole thing!
**hugs** Steph
-------------------- ~~I'm not crazy, I'm just a little unwell-I know right now you can't tell~~Matchbox 20
IBS-D,pain.