fiction: young woman leaves channel islands after death of step grandmother and tries to solve the mystery of a missing child while becoming baby sitter to rock star

[Allison]

I read this around 18 months ago. a young woman's step grandmother asks her to find a woman who was born at the beginnig of WW11. The grandmother gave little information so the young woman moves to London to search. the book is split between the young woman's detective work and finding work as a nanny for a rock couple. The step grandmother acted informally as a painters model.

[Ayshe]

Before I Met You by Lisa Jewell?

[Kris]

Here's the Google Books preview of Before I Met You by Lisa Jewell - Ayshe's suggestion - https://books.google.com/books?id=IZl... There are different cover images.

[Lobstergirl, au gratin]

Allison, are you still looking for this or did you find it?