Mummy Dearest by Joan Hess.
Claire Malloy and Peter Rosen are finally married. They've headed to Egypt for their honeymoon -- sort of.
Peter went ahead to take care of some mysterious business in connection with his new mysterious government job. Claire, her daughter Caron, and Caron's friend Inez follow, and check into the Winter Palace hotel in Luxor.
When they arrive, Claire is greeted by the resident expatriate contingent, mostly Britons, who are thrilled to meet such a famous sleuth. (Once they found out the name of the new arrival, they Googled it to find out all about her.)
Although Claire's intent is to have as relaxing and romantic a honeymoon as she can with two teenagers around and her new husband working, of course it doesn't turn out that way.
Joan Hess accompanied Elizabeth Peters (author of the Amelia Peabody mysteries) to Egypt in 2005 and this book is the result. It's one of the best I've read in this series, as Hess pays tribute some classic mystery writers such as Agatha Christie.