Gandhari was the daughter of Maharaja Subala, the King of Gandhara, and in her maiden state she worshiped Lord Siva

Expressions researched:
"She was the daughter of Maharaja Subala, the King of Gandhara (now Kandahar in Kabul), and in her maiden state she worshiped Lord Siva"

SB Canto 1

Gāndhārī: The ideal chaste lady in the history of the world. She was the daughter of Mahārāja Subala, the King of Gāndhāra (now Kandahar in Kabul), and in her maiden state she worshiped Lord Śiva. Lord Śiva is generally worshiped by Hindu maidens to get a good husband.

SB 1.13.3-4, Purport:

Gāndhārī: The ideal chaste lady in the history of the world. She was the daughter of Mahārāja Subala, the King of Gāndhāra (now Kandahar in Kabul), and in her maiden state she worshiped Lord Śiva. Lord Śiva is generally worshiped by Hindu maidens to get a good husband. Gāndhārī satisfied Lord Śiva, and by his benediction to obtain one hundred sons, she was betrothed to Dhṛtarāṣṭra, despite his being blind forever. When Gāndhārī came to know that her would-be husband was a blind man, to follow her life companion she decided to become voluntarily blind. So she wrapped up her eyes with many silk linens, and she was married to Dhṛtarāṣṭra under the guidance of her elder brother Śakuni. She was the most beautiful girl of her time, and she was equally qualified by her womanly qualities, which endeared every member of the Kaurava court. But despite all her good qualities, she had the natural frailties of a woman, and she was envious of Kuntī when the latter gave birth to a male child. Both the queens were pregnant, but Kuntī first gave birth to a male child. Thus Gāndhārī became angry and gave a blow to her own abdomen. As a result, she gave birth to a lump of flesh only, but since she was a devotee of Vyāsadeva, by the instruction of Vyāsadeva the lump was divided into one hundred parts, and each part gradually developed to become a male child. Thus her ambition to become the mother of one hundred sons was fulfilled, and she began to nourish all the children according to her exalted position. When the intrigue of the Battle of Kurukṣetra was going on, she was not in favor of fighting with the Pāṇḍavas; rather, she blamed Dhṛtarāṣṭra, her husband, for such a fratricidal war. She desired that the state be divided into two parts, for the sons of Pāṇḍu and her own. She was very affected when all her sons died in the Battle of Kurukṣetra, and she wanted to curse Bhīmasena and Yudhiṣṭhira, but she was checked by Vyāsadeva. Her mourning over the death of Duryodhana and Duḥśāsana before Lord Kṛṣṇa was very pitiful, and Lord Kṛṣṇa pacified her by transcendental messages. She was equally aggrieved on the death of Karṇa, and she described to Lord Kṛṣṇa the lamentation of Karṇa's wife. She was pacified by Śrīla Vyāsadeva when he showed her dead sons, then promoted to the heavenly kingdoms. She died along with her husband in the jungles of the Himalayas near the mouth of the Ganges; she burned in a forest fire. Mahārāja Yudhiṣṭhira performed the death ceremony of his uncle and aunt.