Case Study Using Utilitarianism

How to determine the best outcome of a situation using utilitarianism? I have to examine a sexual abuse case using utilitarianism, but I do not know which course of action would be considered to have the best outcome according to utilitarianism: by outing the abuser, you disrupt the family’s peace and happiness and all of their acquaintances. By keeping silent, you sacrifice your own happiness for others’ peace of mind. But by denouncing the abuser, you may encourage other people to do so, spurring on their happiness in turn. I’m just very indecisive.

Hw prompt attached.

I only need some guidance as to how I should close it off.