I found a description for a hardcover book published in 2000.
A car accident places 14-year-old Allison Blair in the hospital,
sunk deep into a coma. She wakes to find she has traded bodies with
Becky Lee Thompson, a girl from California wine country and the
year 1906. While Becky struggles to keep Allison's injured body
alive, Allison must figure out whom to save from death--Becky, or
her boyfriend, Joshua?
originally posted by anonymous cj on 2004-11-11, no edits, entryid=2209