I want to say this book was set in the 1950s – I read it as a child in the 1970s – part of the collection of young adult books at the Jonesboro Library in Jonesboro, AR.

It was about a young teen girl who was plump and had some skin problems. She had an older sister who was slender.  I remember one specific scene – the younger girl was eating a tuna salad sandwich for lunch and her sister told her she shouldn’t eat that because it was bad for her skin. She was going to do her usual sneering retort, but instead she asked her sister what she should eat instead – what she was having? The younger sister started paying more attention to her appearance. She met a boy who was new in town – her parents invited his parents over for dinner (I think they worked together). She put on too much of her sister’s makeup and borrowed heels and made a grand entrance to the dinner. Her parents were horrified and sent her back upstairs to change, so she was humiliated. The boy actually did like her already, but she didn’t have any self-confidence. Over the summer she started eating better and slimmed up. She eventually ended up with the boy who said he’d liked her all along.