The addition of Yibum changes the famous story about Shlome HaMelech completely. One thing I don't understand. How can the Mother in law fall to Yibum? Her Daughter in law married her husbands SON. Obviously the daughter in law can fall to Yibum, but not the mother. Neil BLavin
A woman can fall to Yibum if her husband had children and they all died before he died. In the case brought before Shlomo ha'Melech, the mother-in-law's son had died before her own husband died. Thus, the daughter-in-law fell to Yibum first, and then when her husband's father died, her mother-in-law fell to Yibum, because her husband had left no living children.