Karen Best is a big girl with a big personality and a big love of Chardonnay, which occasionally causes her to make some big mistakes with men. But the biggest thing about Karen is her big heart, which she uses to excel at her job as a counselor at an independent living residence for young adults with Down syndrome. And sometimes, Karen's need to stand up for all the little people in life manifests into a fantasy rock music number, where we discover she also has a big and beautiful voice.