When I was a sophomore my best friends step mom died. She lived with her dad and step mom. I guess she couldn’t stand to stay in their house anymore because she showed up at our house and basically just didn’t leave. My mom and dad never said a word about it.
Eventually she started staying at our house less and less.
Young folks deal with death the best they can on their own terms, I often have thought staying with those outside family members lets them do so... to stay with family they often feel the weight of others grief and a sense of staying strong for them.