I'm trying to idenitfy the title and author of a book that I really enjoyed in the late seventies from the plot. Can anyone help?

[Sjell]

Written by an English female author, it is the story of a young girl (Elizabeth?) and her relationship with an older man (John?) who she meets when cooking for a dinner party at his house as an outside caterer. She and her brother have lost their parents in an accident. John and she fall instantly in love and he turns out to be rich with three houses around the world. They are blissfully happy for a short time despite other people's objections to the age difference. Then he drops dead of a heart attack. It is much better written than this trite summary makes it sound. Does anyone else remember it?

[maggiebee]

This is a good site. Have used it many times.
http://www.whatsthatbook.com/