K. M. Peyton
Pseudonym of Kathleen Wendy Peyton
Locus1 says this is a pseudonym for the writing team of Kathleen Wendy Peyton & Michael P. Peyton. Library of Congress cites <i>Contemporary Authors</i> as listing works by KWHP as Kathleen Herald; under joint pseudonym K.M. Peyton; and individually as K.M. Peyton (some illustrated by Mike Peyton). The latter may be the largest class.