I've not read it, although maybe I ought to have done. It seems Hitchcock used Du Maurier's writing for inspiration several times, cause Jamaica Inn and The Birds are also films of his.
Dirty Dancing is more of a coming of age story, with family conflict, and lots of dancing, an excellent soundtrack, and Patrick Swayze, there's romance and it's part of the coming of age, but in some ways I feel as if the coming of age piece out-shines the romance.
I'm pretty certain based on my knowledge of it, that you couldn't call it anything resembling a healthy romance.