re: Memory loss
A page on Versed is used to "relieve anxiety and/or impair memory."
Given the fact that a local anesthetic and Valium had already been administered, it could easily be assumed that the specific function of the drug was to cause the girl to have no memory of the operation.
Since I'm not a doctor, though, and have no idea what Versed is routinely used for, I'll gladly give the doctor the benefit of the doubt on this. It just sounded a bit odd as written.