Each of the brothers married the woman and then died before he had any children with her. This can be stated clearly. Alternate translation: "Eventually all seven brothers married that woman one by one, but none of them had any children with her, and one by one they died" (See: [[rc://en/ta/man/jit/figs-explicit]])
This is a metaphor for children. In this context it refers to a son. See how you translated this in [verse 19](./19.md). (See: [[rc://en/ta/man/jit/figs-metaphor]])