Sforno on Numbers 30:2/ספורנו על במדבר ל׳:ב׳

1'וידבר משה אל ראשי המטות....זה הדבר אשר צוה ה, G’d had commanded the basic legislation at Mount Sinai when He had said (Leviticus 19,12) ולא תשבעו בשמי לשקר וחללת וגו' “do not render a false oath in My name and thereby desecrate it.” The plain meaning of that verse had not been that you must not deliberately swear falsely, but that having sworn you must honour your oath in all its details. A woman who is married and therefore subject to restrictions imposed upon her by the authority of her husband, is not considered as having desecrated G’d’s name when violating her vows or oath on that account, provided her husband had declared her vow void.