Question About Character Transfers

Okay, so I have a quick inquiry regarding character transfers. Once upon a time, I heard that character transfers could be done across accounts with only the last name being the same, disregarding the first name. That is why I am asking this question on behalf of my friend.

Okay, so my friend is a tranny, and have since gotten a sex change, and all the legal documents done and over with. However, when she called up blizzard to have the legal documents changed, she was told to get a court order or something directed at blizzard to change it. She just didn't want to put up with the hassle so she made a brand new account with her new legal name. However the last name is the same.

She wants to know, if she can transfer her old characters on her old account with the male name, to her new account with her female name.

Also... this question is just from me, has nothing to do with her at all. Since she got a sex change and her account is still in her male name, wouldn't it void something somewhere? Being that the old legal owner of that account doesn't exist anymore?