Request #432 From Cathie

 I have been looking for decades for a book I read in the late 60”s or early 70’s. It was about a late high school or early college aged girl who took a job as an au pair looking after two children on a cruise ship. One of the children I’m pretty sure was named Candy; I don’t remember the brother’s name or the name of the protagonist – Joanna maybe? At one point in the story there was a costume party and Candy went as “the order of the bath”. I’m reasonably sure but not 100% sure that it was written in first person and I think the author’s name might have been Harrington or something similar. It was a mystery – I think maybe a treasure hunt. t I read the book many times but that’s all I can remember about it.