Michal the daughter of Saul was a kind of tragic figure. Clearly David was in love with her, and visa versa. When Avner ben Ner came to David, David had just one request to make of him, "Bring me back my wife Michal bat Saul." And she saved his life at least one time that we know about against her own father's wishes.
So the fact that she did not have children is sad. But furthermore --who were the descendants of Saul and the Givonim hung? It says in Kings II that five of them were the kids of Michal and then it names the father --the person that was the husband of Merav--her older sister! The Ralbag says that they were raised by Michal, but were not actually her kids. And that makes sense to me. And I can not think of any other possible explanation.
So the fact that she did not have children is sad. But furthermore --who were the descendants of Saul and the Givonim hung? It says in Kings II that five of them were the kids of Michal and then it names the father --the person that was the husband of Merav--her older sister! The Ralbag says that they were raised by Michal, but were not actually her kids. And that makes sense to me. And I can not think of any other possible explanation.