Lilian Jackson Braun
I read this book years ago – decades even – when my mother still lived in the US, and we used to hit the library together every weekend, sometimes with my grandmother, sometimes not, and take home as many books as we could carry. Together, we worked through all of this series, as well as many others.
In any case, this book was originally published in 1966, but it manages to hold up pretty well, considering, and it's the first in a long series of cozy mysteries about reporter Jim Qwilleran and his crime-solving Siamese cat KoKo.
These books aren't intellectual in the slightest, but they're full of great characters, gastronomic and architectural delights, and mild mysteries that are completely lacking in horror and gore.
Perfect for afternoon tea.
Or for sharing with your mother.