My Diary from the Edge of the World, by Jodi Lynn Anderson (Aladdin, November 2015), is a road trip from Maine to California (followed by a boat trip to Antarctica) through a fantastical version of the United States (where dragons, sasquatches, and all manner of "magical" creatures exist along side the local MacDonalds). 12 year old Gracie's family--parents, self, big sister, and little brother, plus an orphaned boy (parents killed by sasquatches) her age escaping foster care--didn't want to hastily abandon their big old house in Maine to crowd into a camper van and head out west, a west with no certainty of roads, let alone safety from hostile fantastical critters. But the death Cloud didn't leave many options.
In Gracie's world, Dark Clouds will quite often come looking for people who are going to die, and sort of cloudily engulf them in a deadly way. And Gracie's little brother is sickly and puny, so when a Dark Cloud starts heading down their street, little Sam is its obvious target. So the family tries to outrun it, trying to keep ahead of it until they can leave their world and its Dark Clouds behind forever.
For Gracie's father, found of thought experiments involving string theory, believes in the existence of another version of Earth, a place with no dragon or deadly mermaids or Dark Clouds. But even if this other world exits, can the family camper van make it to the edge of the world with the family intact? (Well, no, because the other Earth lies of the edge of Antarctica, which requires a boat, which has to be sailed through a sea of ghost pirates etc.).
The story of this trip is told in the form of Gracie's diary, and she is a fine diarist, capturing not just the external marvels and dangers and shifting scenery, but, as her skill and insight become more practiced, capturing her understanding of her family as well. It is a gripping family, and a gripping world, and this road trip through it, involving witches, pegusi, and a Guardian Angel the family hires in California, that makes for good reading. Gracie's voice is lively and personable, and the descriptions are vivid as all get out.
My only reservation is that Gracie keeps saying that her mother thinks of a her as a frisky, daredevil, circus-going-on-inside-her kid, yet Gracie just sits there in the Winnebego, writing. She's never much more than a passive observer, which I found a bit frustrating. On the other hand, it was nice to have a story with two parents both present and caring, even if the Dad is a bit of a caricature of a wooly minded professor and somewhat absent even when physical there.
Short answer--a sure thing for the fantasy loving, writing inclined, 11 year old girl (especially one with an annoying older sister). Also a good one for anyone who wants their fantasy mingled with speculations on string theory!
Here's the Kirkus review, which more or less agrees with me (I think there are at least two Kirkus reviewers of MG SFF, one of whom agrees with me and one who gets things badly wrong. It is the later one, for instance, who didn't blink when Unusual Chickens for the Exceptional Poultry Farmer ended up in the regular MG section of their Best Of list, despite being obviously fantasy....)