Mourning loved ones who have passed away is not an easy thing for anyone. It is not reality, and such comfort cannot satisfy and will not endure. Even when Jesus died, the people wanted to do something. Joseph of Arimathea took care of Jesus' body by putting it in a nice tomb. The women wanted to anoint His body with spices.
Some ancestor worship is done to make the living people feel better in the midst of their mourning.
It is contrary to God's commandments, but it is understandable. When there is no hope of heaven, there can be only weak substitutions for genuine hope and comfort. Often the offerings to a dead loved one are made, not just because of sorrow, but also because of fear. The surviving family members are afraid that if they do not honor the ancestor correctly, the spirit will give them bad luck. She had no answer.