Who Parvati is
Parvati is the one who decides. Shiva sits still on his mountain; she is the reason anything happens there. She was born the daughter of Himavat, king of the mountains, and his queen Mena, and before she was old enough to say why, her heart was fixed on the ascetic who sat on the slopes above her father's house. When beauty did not move him she went into the forest and won him the hard way, and the Puranas never let anyone forget that she did the winning.
The first day she met him she told him what she was. He had just called a woman a trick of illusion and told her father to take her home. She bowed and answered that the energy of his penance was hers, that his seeing and hearing and speaking were hers, that she was Prakriti and he was Purusha, and that if he was truly the greater he had nothing to fear from her sitting nearby. He laughed, and let her stay.
Everything after that is her doing. She is the mother of Kartikeya, who had six nurses and still called her his mother, and of Ganesha, whom she shaped with her own hands. She is half of Shiva's body, in the form the temples call the lord who is half woman. When he called the world an illusion she withdrew from it, and the world went hungry until he came to her door in Kashi with a begging bowl; there she is Annapurna, the one with the full plate. She beat him at dice and took his loincloth. She covered his eyes in play, darkened the worlds, and paid for it with her own penance on the hill of fire. In Madurai she is the queen Meenakshi, born from a sacrificial fire and raised as a prince. In Bengal she is Durga, who comes home to her mother's house for three days every autumn, and in Karnataka she is Gauri, fetched back to Kailash by her own son the morning after she arrives.
The Shakta tradition reads all of these as one goddess, and reads that goddess as the power without which Shiva cannot so much as stand up. Her festivals are women's festivals. Teej in the monsoon, Gangaur in the spring, Gowri Habba the day before Ganesh Chaturthi, Durga Puja in the autumn: each is kept by one woman at a time, for a husband, a daughter, a homecoming. The hymn sung to her at Kashi ends with a line that every one of them could say.
Mata cha Parvati Devi, pita Devo Maheshvarah: my mother is the goddess Parvati, my father the god Maheshvara.
