story identification - Mother & son flee step-father with an airstream trailer; machine that can change printed text

Read a book about 30 years ago that had a boy and his mother fleeing his step-father. Much of the story is told in flash-backs so it is not readily apparent why they are fleeing. They go to his grandparents’ home and borrow a trailer. Pretty sure it is an airstream (talked about the shiny aluminum). I remember at one point, the boy befriends a young, female librarian, but they have to move on. They later encounter her again and I recall the boy being impressed by how well she handled the trailer (it had been a big deal that it was difficult to back up with it).

SF element: during one of the flashbacks, the boy had an argument with his step-father and later goes to read a book (his favorite?) and there is now a passage in it that is addresses him directly discussing how he was wrong with his argument. The step-father is involved with a group that has some machine that can change the printed word to whatever they want.

Additional details I’m not certain of: seems like the “machine” involves nanotechnology and isn’t as controlled as one would wish (perhaps some incidents of wiped text and spots changed to illegible passages). I also feel like the librarian is encountered in San Francisco. I feel like the step-father was abusive and the boy is certainly upset about the ability to change books, but not sure why the mother finally fled. When re-encountering the librarian (and depending on her to move the trailer), I think the mother had been captured and they had to initiate a rescue plan.

Answer

As per this other person looking for the same book, Wordchanger by Mary Haynes.

An update, having read Wordchanger this evening:

• The device does use neutrinos, but only affects books within some (unspecified) radius of the device itself, not all copies everywhere. It's never explained how the device is controlled. (Updike's poem doesn't appear in the book.)


• The protagonist is 12 years old, but does at one point briefly drive a car towing an Airstream trailer. The other protagonist, whose story is interleaved for the first half of the book until she joins up in the middle, has a librarian friend who drives the trailer in reverse, having acquired this skill driving the bookmobile. The two protagonists aren't siblings, but might as well be.


• A passage in "Carry on, Mr. Bowditch" is changed, and the protagonist's name is changed on his passport.



• The antagonist is indeed the stepfather (plus vaguely threatening men from a secret government agency).