I'd type it and make it sound as professional and non-emotional as you can. I'd also say in the letter that you expect a response by a certain date (probably 30 days) and give your address and phone number.

I would make sure that you are OK to read the notes if she does provide them...that you have someone to talk to about it, etc. I recently had a horrible experience with a medical doctor and requested the notes from that visit. I found them very upsetting...mostly because he lied about some things. But that was just one visit...6 years is a long time.