"When Kristy Thomas has the great idea to form a baby-sitters club--a chance to earn money and spend time with her friends, all while doing something they each love to do--she has no idea how much the club will change everything. Crank calls, uncontrollable toddlers, wild pets, untruthful clients . . . running a business is hard work! Kristy and her co-founders, Mary Anne, Claudia, and Stacey, are sure they can handle anything. But only if they stick...

When Claudia's beloved grandmother Mimi has a stroke, it changes everything. Instead of spending the summer baby-sitting, Claudia is Mimi-sitting. She could use a little help, but her impossible sister Janine just can't be bothered.

When Karen shows off her roller-skating expertise and accidently crashes into her brother, she ends up with a broken wrist but uses the opportunity to get everyone she knows to sign her new cast.