She should realised it was a scam event from the start. Singapore airspace will not allow such an event as it will cause problems for planes flying overhead.
The release of balloons or lanterns in large amounts with no control of direction and height once it is in the air, even if they were to be tied to strings cannot guarantee no incidents of escaping balloons or lanterns. Also, what if the lanterns caught fire and fell to the ground? Will it hit someone in town or will it be a fire hazard? Singapore authorities will not take the risk and will not approve of such an event.