A sensor system and seat assembly includes a sensor assembly configured to detect a seating force exerted on a portion of a seat cushion of a seat. The sensor assembly includes a base, a force transducer configured to output a signal indicative of the seating force, and a lever pivotably coupled to the base. The lever defines a sensing end configured to be disposed proximate to the portion of the seat cushion such that the seating force operates on the sensing end. The lever also defines an actuating end configured to apply an actuation force to the force transducer. The sensor assembly may comprise a plurality of levers. Each sensing end of each lever may be disposed in a separate location within the portion of the seat cushion. The sensor assembly may be configured to detect a child exerting a seating force on a portion of the seat cushion.