This is one that can easily vary from state to state. If the policy had any value, and also may be impacted by the language of her divorce decree or separation agreement.
Have her consult counsel who knows insurance law.
If the state law says the beneficiary designation of an ex-spouse lapses on divorce, and requires a filing of a new bene designation or language in the divorce decree, and thus there is no beneficiary, the insurance company would pay a "contingent beneficiary" if any and if none, the deceased's estate in which case the money ultimately goes according to his Will or the laws of intestate distribution of his state.
If challanged the isnurance company would "interpleaed", depositing the proceeds in court and letting the rival claimants fight it out.
