Photo of Kathy Marshall, a.k.a. The Queen of Surf Guitar dueling with Eddie and The Showmen via The Sound of Surf.
"She was a 13 year old girl named Kathy Marshall. She didn't have her own band, but she did sit in with several of the top bands of the day. Kathy was a frequent member of legendary surf bands Eddie and the Showmen, The Blazers, and The Crossfires (who later became The Turtles). There were no releases with her guitar on them, but her double picking talent made quite a stir in those days. Her on-stage rivalry with Eddie Bertrand was a major draw during Eddie and the Showmen's peak year as house band at the Retail Clerk's Hall in 1964. Once, Kathy even played with Dick Dale. He introduced her, and then she broke into The Wedge. Her fire caused him to first step back and watch, then take off his guitar and stare, then finally throw up his hands and walk off stage."—Reverb Nation
[Thank you to Rebecca of Have Love, Will Travel for the intel!]