Young adult (teen) novel in which 2 girls who were friends become mad at each other for some reason I can't remember and aren't friends anymore for a while. I probably read it in the 80's or maybe early 90's and it was probably written around that time. Probably a woman author. The girls are probably around age 12-14. SPOILER:I think it resolves at the end when they are both at a sleepover, and when one of them wakes up in the morning she discovers her former-friend has wet the bed (peed in her sleeping bag), and so she spills her drink (it was a coke I think) on her friend's sleeping bag to cover up the fact that her friend wet the bed. The friend wakes up and is grateful when she realizes why her friend spilled the coke, and they become friends again.
Eight-year-old Collette Murphy loves her younger brothers and sisters, but sometimes there are just too many Murphys. When her parents set aside one day for Collette to have all to herself, Collette realizes how much she appreciates her brothers and sisters.