Amanda is Winnie's best friend in 10 and most of 11. However, they slowly begin to outgrow each other. Amanda leaves Winnie for Gail.
She helps Winnie plan for her eleventh birthday party.
In Twelve, Winnie and Amanda go to Camp Winding Gap because Gail went to equestrian camp.
After the yellowjacket incident, Amanda calls Winnie but Gail is on the line waiting to talk to Amanda, and Amanda promised Winnie she'll call back, but she didn't and they stopped being friends again.