When I asked her to share the specific verses from the Bible, she kindly sent me these:
Mark 10:11-12 ASV
And he saith unto them, Whosoever shall put away his wife, and marry another, committeth adultery against her: [12] and if she herself shall put away her husband, and marry another, she committeth adultery.
Luke 16:18 ASV
Every one that putteth away his wife, and marrieth another, committeth adultery: and he that marrieth one that is put away from a husband committeth adultery.
1 Corinthians 7:39 ASV
A wife is bound for so long time as her husband liveth; but if the husband be dead, she is free to be married to whom she will; only in the Lord.
Romans 7:1-3 ASV
Or are ye ignorant, brethren (for I speak to men who know the law), that the law hath dominion over a man for so long time as he liveth? [2] For the woman that hath a husband is bound by law to the husband while he liveth; but if the husband die, she is discharged from the law of the husband. [3] So then if, while the husband liveth, she be joined to another man, she shall be called an adulteress: but if the husband die, she is free from the law, so that she is no adulteress, though she be joined to another man.