Wondering When My Sister In Law May Have Died. She

Wondering when my sister in law may have died. She was found deceased Thursday May 26. A neighbor thinks she saw her kitchen light on Tuesday May 24. My sister in law may have weighed 100lb but when funeral home got her body and we got to see her for 1st time she was so bloated. Is there anyway to predict or estimate when she may have actually died. The funeral home said they had to put her death down as the day she was found.