2,818. When a Betrothal Is Dissolved by Death or Divorce

Hilchos Nedarim 11:10

If the naarah’s fiancé dies, she returns to her father’s domain and her vows can be annulled by her father alone as was the case before she was betrothed. If her father died after she was betrothed and she made a vow after his death, her fiancé can’t annul it alone. This is because a man doesn’t acquire unilateral vow-canceling ability until his wife enters the chuppah.

Hilchos Nedarim 11:11

Let’s say that a betrothed naarah makes a vow, which her father hears but her fiancé doesn’t. That same day, she is divorced by her fiancé and then betrothed by someone else. Even if she is divorced and betrothed 100 times, her father and the last fiancé are the ones who can annul the vow she made while betrothed to her first fiancé. This is because she never entered her own independent domain; she was in her father’s domain the whole time because she’s still a naarah.