Sleepovers by Jacqueline Wilson - old paperback
Amy, Bella, Chloe, Daisy and Emily are friends at school and have their own Alphabet Club (just look at their initials!). Daisy is the newest member and is desperate to fit in, even though Chloe is distinctly unfriendly to her at times. Throughout Daisy's first year at the school, the girls plan ever-more elaborate sleepover parties for their birthdays. Daisy is dreading the time when her birthday comes round as she doesn't know what her friends will make of sleeping over at her home, with her rather special older sister...
A superb handling of both the intricacies of young, female friendship and the joys and problems of having an older sister with learning disabilities, from our most accomplished and bestselling author.