Margaret Erskine (1901-1984) was the pseudonym of Margaret Wetherby Williams, who was born in Ontario, Canada and grew up in Devon. Her series character was Inspector Septimus Finch.
I enjoyed this and I'll definitely try this author again, not least because the girl with a lot of men friends (a self-described 'marauder', which is fun!), when she fetches up dead, is not blamed for her own murder. In a refreshing twist everyone is like "Oh no men who do murders are the actual problem".