Backstabbing family members!?

My sister recently died. I have a large primary family. When this death occured, my extended family members assisted with the details of her death and arrangements. Some private things came out and now some of my extended family are aware of some very personal details of my sister's life before I and my other siblings could know first. Since my deceased sister lived with a roommate; this room mate took the belongings of my sister before any of us could. Some of my extended cousins have information on my sister's passing without asking us if it is ok for them to know. We just feel disrespected...like her passing allowed a free for all attitude on her belongings before we, her siblings could collect. How would you deal with this?? Keep in mind that these people are my blood relatives.