What did gilly think would drive mrs trotter wild?

Gilly believed that Mrs. Trotter would be driven wild by the prospect of being in control and having her authority challenged. She thought that Mrs. Trotter, who was strict and uptight, would be particularly agitated by any disruption to her carefully maintained order. Gilly's antics were intended to provoke a strong reaction from Mrs. Trotter, showcasing her desire for attention and a sense of power.