What would you do?

I recently learned that a close family member has a pain pill habit.
this person is currently in jail and is on their way to a 6 month treatment program.
I discovered said family member stole some pain meds from me prior to their incarceration. their spouse informed me during a argument they were having. the bottle was presented at their house. My wife checked, I'm missing about 180 vicadin.The VA was giving me the damn things like candy and my family has a history of abuse, I refuse to fall into that, so I never took them.
I am the only person who seems to want to help this person, but they make it tough. Right now I am hated due to some custody issues.
I have decided that I am sick of being taking advantage of and used, then tossed aside when I'm not an asset any longer.
I would like the opinion of folks who have no dog in this fight, would you report the theft of the drugs?
this would mean the following: violation of probation, and a felony 3 charge and likely 3 yrs in prison.
or just let it go?
I'm afraid that if I do, this person will OD and die.
I'm at wits end with this, I've asked family, but they're all over the place with this.