[Al Bundy]

Originally Posted by Katipan

Show her how it's done?
Make her get a tongue piercing?
Ask her mother to talk to her?
Or maybe your mother?
Have her hold a mouth full of water, but still be able to suck through a straw.
Put a bunch of marbles in her mouth and have her practice flicking them around with her tongue.
Teach her to tie a cherry stem with her tongue. Not sure this helps you, but her girlfriends will enjoy it.
Get her drunk.
Or upside down.