Rashi: Because she is neither under the jurisdiction of her father ¹ nor of her husband. ²

Moshav Zekenim: Because in the case of an Arusah whose father handed her over to her husband's Sheluchim [to bring her to Chupah], and he died, ¹ it needs to teach us that is as if she had Chupah and that her father can no longer annul her Nedarim.

Yevamos, 87b: The Torah is referring to a case where her father handed her over to the Sheluchei ha'Ba'al and she become widowed or divorced on her way to the Chupah - and the Torah is teaching us that, since she left the jurisdiction of her father - albeit for only a short time, she does not return to his jurisdiction and he cann no longer annul her Nedarim.

Nedarim, 89a: The Torah is referring to a married woman who declared Nezirus, became divorced and remarried (or widowed and married to someone else) on the same day. Her Nedarim stand, since her husband cannot annul her Nedarim retroactively, even Nedarim that she declared whilst she was married to him the first time. ²

Nedarim, 89a: The Torah is referring to an Almanah or a Gerushah who marries after declaring that she will be a Nezirah after she is married. Her husband cannot annul her Neder, because she declared it before the marriage. ³