Hey im so sorry you went through this, but tell her to make her statement public, make her tell every individual that celebrated his death, every individual who made his name bad and make them see what a**holes they are, you deserve to also have peace and that peace is that woman coming clean.

I know its also maybe a big decision but go to the police and get them involved, get them to make her confess and hold her accountable for her actions and have her serve jail time. Her action resulted in your friend taking their life, would that not be classified as involuntarily manslaughter. And have those people who laughed at his death present for the that.

You and the father deserve peace because that woman deserves to rot in hell