The Doll in the Garden: A Ghost Story, by Mary Downing Hahn (1989, middle grade, 128pp), is both time slip and ghost story. It's also a very fast read, great for a nine year or ten year old girl who likes spooky books.
When Ashley and her mother move into the upstairs apartment carved out of a grumpy old lady's house, they are hoping to make a new life for themselves, one without Ashley's dad, who had recently died of cancer. Part of the garden is well-cared for, but it is the overgrown tangle of weeds and roses at the other end that draws Ashley.
There she meets Kristi, the little girl who lives next door, and hears from her that this garden is haunted---every summer, a white cat appears, and in the night, a child can be heard crying...But its charms are too great to resist, and soon Ashley and Kristi are busy clearing away weeds, making a place for themselves.
Then, partly buried, they find a box, and in the box is a beautiful old doll, interred there long ago. When the old landlady happens to see it, she is furious, and demands that Ashley hand it over too her, and Ashley has no choice to obey.
But it's real owner is still waiting for her doll, beyond the overgrown garden. Following a white cat with no shadow, Ashely finds herself outside a house that doesn't exist anymore, and there, in the past, she meets Louisa:
"Her eyes were huge and darkly shadowed, and her skin was milky white. She gasped and clasped her hands over her chest. "Who are you? " she asked. "Where did you come from?"
For a moment I couldn't speak. Was I staring at a real girl or a ghost? If I answered her, would I be caught in this place forever?" (p 55)
Louisa is dying...and wants her doll back.
That's the plot--straightforward, but tidily done, one that allows Hahn to add a thoughtful substrata of stories of friendship and loss to the supernatural surface.
The book bills itself as a ghost story, but in fact the only ghost--dead spirit from the past in the present--is the white cat. It's much more a time slip story, even though the time travel is somewhat limited, consisting of handful of visits to Louisa's time, with no exploration of the larger past. This is is all the story needs to work, but this isn't one that will teach the reader anything about other times. It is, however, fast-paced and atmospheric, and, as I said before, one the nine or ten year old girl should like lots.
In one of those strange blogging coincidence, Peter at Collecting Children's Books mentioned this book just after I had finished reading it. He was discussing Kansas' William Allen White Award, which The Doll in the Garden won in 1992.