1,828. Dissolving Yibum

Hilchos Geirushin 11:17

If a girl severs the bond of yibum (levirate marriage) through refusal, she remains prohibited to the brother-in-law’s father (who was also her deceased husband’s father). She appears to be his daughter-in-law because that’s what she was when his son, her husband, died. She may, however, marry other members of the family. The consequence of this is that even though she used refusal to reject yibum with one of her late husband’s brothers, she may still marry another of his brothers.

Hilchos Geirushin 11:18

If a woman is divorced or widowed, she may not marry or be betrothed until 90 days have passed from the day she was divorced or widowed. This is necessary to determine whether or not she’s pregnant, so that, if she is, the child’s paternity should be clear.