Say a sharp NO like you've been doing and then turn your back and stop playing with her. She'll get the idea quickly. Bite moms hair = no play.
An idea you may want to try is to spray bitter apple spray in your pony tail (probably after work I don't know what it would do to your pony tail- it might be like super strong hair gel lol
) so she gets a bad taste in her mouth when she bites your hair.