In the Liber Angelis section of the Book of Armagh (attributed to Patrick) an angel grants Armagh supremacy over (almost) all other churches in Ireland and the right to collect tributes. Brigid alone is granted independence and is not required to pay tribute to Armagh.
As founding abbess of Kildare her status was on par with that of a bishop, and she enjoyed an extremely close friendship with Patrick. The Book of Armagh states "Between St. Patrick and Brigid, the pillars of the Irish people, there was so great a friendship of charity that they had but one heart and one mind."
St. Brigid's feast day also marks the beginning of spring with the celebration of Imbolc, the halfway point between winter solstice and spring equinox.