I think the blonde was just a special guest for the tour.
I like Candy Givens - probably not 24/7, but she had a voice. It came from the soul, she sometimes sounded like a wounded animal, not like someone doing vocal acrobatics and what is that fancy word Dave always uses ... melisma!
(Tommy and his Echoplex - LOL!)
Sure, she must have heard her share of Janis (and Janis' black predecessors), but so what. Not many white girls can sing like that, especially at her tender age.
And she was variable, she could do a Carol King singer/songwriter voice too.
In the end she became a drug casualty, just like her band mate Tommy. Zephyr were a tragic band.