Her husband may be stressed selling his new budget, but Michelle Obama sure is happy.

The first lady danced briefly to the hit Pharrell song “Happy” Thursday at Edward A. Reynolds West Side High School on the Upper West Side, where she announced a $500 million donation from the Robert Wood Johnson Foundation to expand efforts to end childhood obesity.

Obama also watched students make smoothies and take a spin class on stationary bikes. She praised Principal Jean McTavish for getting skinless chicken breasts on the lunch menu and filling the vending machines with healthy snacks.