Dr. Tess Coleman (Curtis) and her 15-year-old daughter, Anna (Lohan), are not getting along. They don’t see eye-to-eye on clothes, hair, music, and certainly not in each other’s taste in men.
One evening, their disagreements reach a fever pitch -- Anna is incensed that her mother doesn’t support her musical aspirations and Tess, a widow about to remarry, can’t see why Anna won’t give her fiancé (Harmon) a break. Everything changes when two identical Chinese fortune cookies cause a little mystic mayhem.
The next morning, their Friday gets freaky when Tess and Anna find themselves inside the other’s bodies. As they literally walk a mile in each other’s shoes, they gain a little newfound respect for the other’s point of view. But with Tess’s wedding coming on Saturday, the two have to find a way to switch back -- and fast.