Right away

Almost as soon as she feels the water running across her breasts she looks down and screams, realising that her bikini top is no where is sight.

Her hands quickly come up to cover her bare breasts and she ducks her shoulders into the water. "Oh my God, where is it?" She gasps, looking around frantically for her missing top. "I need you kids to help me find my bikini!" She quickly tells the children.