I'm trying to find out the name of a book I had when I was very young. It was a hard cover book (in orange fabric type cover as far as I can remember) and it was about friendship. I remember the illustrations were very colourful with orange, green, yellow and pink in them. The book was about 3 friends - 2 girls and a boy - and they were playing in a back garden - a sandpit was in the back garden. They had a fight then made up.... i think the boy was a next door neighbour or something. One of the girls was called Kate (i think), and the book was about 6 inches x 6 inches in size. Would anyone know this book?