Reference for Yevamot 239:5
ת"ש האשה שהלכה היא ובעלה למדינת הים ובאה ואמרה מת בעלי תנשא ותטול כתובתה וצרתה אסורה ר' אלעזר אומר הואיל והותרה היא הותרה נמי צרתה אימא הואיל והותרה ונשאת
is because it was her intention to injure her rival!<span class="x" onmousemove="('comment',' She herself would thereby suffer no disability since she herself is in any case divorced from her husband. ');"><sup>11</sup></span> — If she was married to an Israelite, this would be so indeed;<span class="x" onmousemove="('comment',' There would be ground for suspecting that she was divorced. ');"><sup>12</sup></span> but here we are dealing with one who married a priest.<span class="x" onmousemove="('comment',' Who may not marry a divorcee (v. Lev. XXI, 7). Had she been a divorced woman she would not have ventured to contract such a marriage for fear lest her former husband might return and expose her. ');"><sup>13</sup></span>