When a HB is introduced to a group that you're a part of, getting her attention always seemed harder to me, as you were just "one of them". Discussed it with a friend last night at the bar, and we came up with the following:

As you shake her hand, flip the handshake so that her hand is on top (no one we tried this on noticed), then tell her:

me: "hey, you really can't shake hands like that!"

HB: "why?"

me: "This is how salesmen shake hands. It sends a message to people that you just want to dominate them and be on top, and most people tend not to like that. You should do it like this"

take her hand and show/explain how it's done (kino)

HB: "oh my god, i never even realized i was doing this, blah blah"

and it's on. worked very well for me last night, feel free to test it out :) Also you can make this a game later on, you approach people together experimenting with different handshakes, eye-contact, openers and so on.