"I think it's the fate of the illustrator," she would shrug. "Look at Ernest Shepherd. He was so brilliant and did so much fine work, but people only associate him with Pooh and Piglet, and Toad of Toad Hall. It's the penalty of hitching your wagon to a star."
She believed Lewis to be rather indifferent to her work. "I think he saw them as just a necessary part of a children's book." The author and illustrator only had a couple of awkward meetings in all the years they worked together but apparently Lewis once told George Sayer "Pauline is far too pretty.".
Here's a lovely article about her: http://personal.bgsu.edu/~edwards/baynes.html
and here is her obituary in the Guardian: http://www.guardian.co.uk/books/2008/aug/06/booksforchildrenandteenagers