She succeeded her sister Maharani Gowri Lakshmi Bayi, till her regency was relinquished in favour of her nephew, Maharajah Swathi Thirunal.

As the only female left in the family, Gowri Parvathi Bayi became Regent Maharani on behalf of her nephew, the heir, Maharajah Swathi Thirunal Rama Varma.

Upon her accession she was actively counseled by her brother in law, Raja Raja Varma of the Changanssery royal family, as well as her husband, Raghava Varma, who belonged to the royal family of Kilimanoor The Maharani's first act after coming to power was to appoint a new Dewan or Prime Minister to her state, as Dewan Devan Padmanabhan had died and state affairs were being conducted by his deputy Bappu Rao.

In 1815 Sanku Annavi Pillai was appointed to the position but was soon found to be incapable of handling his difficult office and within two months he was removed.

After ten months, following the suggestion of the British Resident, John Munro, 9th of Teaninich, Raman Menon, a Judge of the Huzhur Court of Travancore was appointed Dewan.

Maharani Gowri Parvati Bayi instituted several reforms in her state during her regency on behalf of her nephew.