Secrets of Redemption
Must be read in order.
The Secret Diary of Helen Blackstone (prequel but can be read at any time).
The Third Nanny is a standalone, separate book.
Charlie Kingsley Mysteries
Can be read as standalones, but you may enjoy the series more reading them in order.
Loch Ness Murder (included in the Mysteries, Midsummer Sun and Murders cozy mystery anthology and can be read as a standalone).
A Wedding to Murder ForÂ
A Grave Error (prequel that can be read at any time).
The Riverview Mysteries
Standalones.
Today I’ll See Her (short story).