Who is that girl???????
She's the one dancing with Frankie in the "Runnin' Wild" number - she's wearing a red shirt and white shorts, she has streaky-highlighted blonde hair, very long, pulled back in a pony tail - she wears it that way throughout the picture. I don't think she has a name, she might be one of the "beach girls". She's featured prominently among the non-principals. In all the beach scenes with dancing, she's right up front.
She's a captivating beauty! I wish I knew her name.