“Firm in their vows” indicate that these excellent women are firm in their vows [to be with and serve] their husbands even in times of extreme crisis.

NOTE. It is important to note that every material activity prescribed in the scriptures is meant for a certain purpose, a certain result to be attained in one’s next life.

As indicated in these verses, these are generally taken advantage of to go to the celestial world of the devas. But these scripturally prescribed material activities also serve a higher purpose: purification of the heart from lust, anger and greed.

Śrīla Baladeva Vidyābhūṣaṇa Prabhu explains in his commentary to Bhagavad-gītā that this is the real purpose behind the duties of the varṇāśrama system. Men and women practicing Kṛṣṇa consciousness with the desire to attain pure love of Godhead would naturally accept these material duties with the desire to attain purification of the heart from lust, anger and greed, and not with the desire for material enjoyment in this or the next life.

It should also be noted that Svarga refers to any of the worlds in and beyond antarikṣa or outer space, and hence can also refer to the spiritual world. Śrīmad-Bhāgavatam 7.11.29 describes the highest possible result of faithfully and properly engaging in strī-dharma as follows:

yā patiṁ hari-bhāvena bhajet śrīr iva tat-parā
hary-ātmanā harer loke patyā śrīr iva modate

“The woman who engages in the service of her husband, following strictly in the footsteps of the goddess of fortune, surely returns home, back to Godhead, with her devotee husband, and lives very happily in the Vaikuṇṭha planets.”