Jennifer's life couldn't be more different from that of her sister, who is married with three kids. Jenny's committed to her job and being a good aunt, but little else. This all changes when her sister takes off to Europe with her husband, leaving her alone with the kids.

As well as guidebooks, Jenny brings her sister Mandy a gift to encourage her to have more fun on her Paris holiday. As Jenny leaves for a date with boyfriend, Quinn, she bumps into Will, Mandy’s new neighbor.

Mandy says goodbye to her kids before she and her husband leave on their long-awaited honeymoon. But suddenly, her parents are unable to provide childcare, and it's too late to hire a babysitter. Can Aunt Jennifer be trusted to fill in?