Anyone know of this mystery series for kids?

"The Famous Five" by Enid Blyton sounds something similiar - is this what you're thinking about? They were written in the 1940s and 1950s. It's been a while since I read them - but I don't really remember a Henry. I remember George's cousins Dick, Julian and Anne, and she had a dog called Timmy. Her parents were Quentin and Fanny, and they lived in a village called Kirrin, and owned Kirrin Island. They ended up going on adventures when they were together during their school holidays.

Sounds like Enid Blyton's 'Five Go to Mystery Moor' (1954) - it involves a tomboy called Henry. George and Anne go to stay at a riding school with Captain Johnson and his wife, and their daughter - Henrietta. Julian and Dick join them later for an exciting adventure.

i love mysteries. a lot that it is not a possibility to p.c.. purely one favourite or perhaps to list each of the authors i love. in this article are a number of my fav secret authors, in no certain order: Lilian Jackson Braun Carole Nelson Douglas Camille Minichino M. R. Sellars Karen Irving Jasper Fforde Sandra Tooley Lee driving force Sir Arthur Conan Doyle Agatha Christie Harry Kemelman Margaret Truman P. D. James Matthew Pearl Martha C. Lawrence Ellery Queen Ralph McInery Tony Hillerman Erle Stanley Gardner Susan Wittig Albert

not sure about that..the Bobbsey twins were Freddy and Flossie