I’m looking for a children’s/ young adult novel I found in a school library in 1977. I thought of it then as an “older book,” so I’m guessing the publication date to be between 1945 and 1965. It’s historical fiction that takes place during Scotland in the Jacobite period. The main character is a teen girl who sometimes has visions via the “second sight,” a gift that allows her to help save the prince at the end. It’s not a Sally Watson book.
I thought it might be “Quest for a Kelpie” by Frances Mary Hendry, but I think that’s too recent… It is very much her territory, though.
https://www.goodreads.com/book/show/2645128-quest-for-a-kelpie
Could this be The Thirteenth Member by Mollie Hunter?