3 Books Found

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"It's a middle grade novel at least 30 years old about a girl who makes a friend at school. I think the friend is named Peggy. She lives alone with her father. She has a pink checked dress she wears more than once. The girl gets together with other friends and they make fun of Peggy. She stops speaking to her at school. One day she disappears. She leaves a photo of them together and no return address. Peggy had a dog. One day the girl went over Peggy's house. She met the father and played with the dog. She had fun. She really liked Peggy. She made a mistake making fun of her later."