My condolences,
Reiki works on the soul as well as the physical body. I beleive your aunt can still benifit from reiki. I will add her to my reiki list.
One thing i did when i got attuned was to send reiki to all my deceased relatives and friends. I felt then that the reiki could help them be at peace.
I will also add your oncle and his son to my list. Hoping it will help ease the pain.
Hope this helps
LadyReiki