the main thing i can suggest (other than a pro) is to try to teach the dog that protecting that person is not what that person wants. most dogs aim to please, and you need to assert the sense that your friend is not Hannahs to protect. vocal scolding and some physical reprimanding may be nessesary. take it small steps at a time. try small, opposite sex, non-dominant dogs at first, and let her see that they are not a threat. move (VERY slowly) to larger, more assertive dogs then to same sex dogs. after you have that mastered (it may be weeks or months later) try a person. most dogs are more comfortable with women, so try that first. a small women (maybe a well educated teen) might be a good idea. make sure they don't smell like other dogs (it wacks some dogs out). also, VERY important, be sure the person you are introducing has a good knowledge of dogs, and they know when to back off. have them make friends with the dog first, then address the human. that way the dog is comfortable with the person before it (in a dogs sense) walks onto her property. hope this helps some!
Leah
P.S. give yummy treats when she reacts well, and scold (harshly) when she is agressive.