What does it mean to say it's a doll in fortune telling?

The fortune teller said that the child has a hundred-day doll, how can he return it? Do you know that?/You know what?

Give it back to the witch A hundred-day doll, under normal circumstances, can't live for a hundred days. Find a fairy to draw a portrait of a doll, write down the name, burn it to an old woman (any old woman gave it to her), and return it. I'm a hundred-day-old doll, and my grandfather is a fortune teller, who was pushed by five lines of gossip. When I was born, my grandfather figured out that I was a hundred-day doll, and he didn't return it or deal with it. After more than a month, he stopped breastfeeding and was weak, so he quickly went to find a witch. After that, it was okay, but he was always sick and had no choice.