Can someone just explain to me what did the mother did exactly? I didn’t understand

Since the MC and ML weren’t sleeping together and having a child, she gave the counselor a drug that induced his heat, which attracts other alphas/omegas to want to sleep with them.

She basically gave MC a choice to either go up to where ML was and sleep with him, or don’t go up and ML will sleep with the counselor instead as he is influenced by the pheromones.