Gonna be expensive, but that park has the better roller coasters and pop culture compared to the other Disney parks.
Universal also appeals to teens with Harry Potter.
Insider tip--Sea World has the best rollercoasters in Orlando, so if they want good rides, that is the best place to be. Also much cheaper.
Consider one or more beach days. Clearwater is 1.5 hours to the west and has the calm, warm gulf water and white sand. Daytona/Cocoa are 1 hour to the east and have the breakers. Late March and on the water starts to warm back up.