1099c cancellation of debt

My mother-in-law received a 1099c cancellation of debt form. It lists her name only and the total amount of debt ($17,000+) forgiven from an auto loan. The problem is that the auto loan had a cosigner (a relative, not a spouse). The cosigner also received the exact same form in their name only for the total amount of debt ($17,000+) forgiven.  Should they both include the 1099c on their respective individual tax returns? Can they split it? It doesn't make sense for my mother-in-law to pay taxes on $17,000+ and the cosigner to also pay taxes on $17,000+ simultaneously when only one debt of $17,000+ was forgiven...