Malbim: If you want Mishpat - what is your claim?

Malbim: The woman against whom she claimed was there. She did not dispute the facts, just she said that their agreement was invalid. No Kinyan can obligate her to kill her son! The claimant wanted the king to use his power to rule outside of Torah law, based on the situation, especially since she enticed her [to kill and share her son].