[rendywussell]

Back in the 70s my 6th grade teacher read the class a book of which I can't remember the title.

It was about some siblings, three I think, who were sent to live with a(n) (older?) relative. They came across a sundial in the backyard through which they were able to travel back through time to the lives of another family of children that use to live in that same very house and to whom a tragedy had occurred. It was up to these contemporary children to save the past children from the tragedy that occurred. Great book. Help

[fairytales]

Moondial by helen cresswell is sounds similar, but it wasn't siblings, just one girl