She sneaks in through a trapdoor to your left, and just like Toy Bonnie, there is no way to prevent her from getting into the room. Your only defense is to put on your Freddy Fazbear mask to fool her. Toy Chica is faster than Toy Bonnie and will invade your office more often, however she is easier to fool with the mask, especially when looking directly at her.

Nothing has changed.