The Supreme Goddess Is The Mother of the Universe, almost identical with the Brahman of Vedanta, but only at the transcendental level. No doubt The Divine Mother IS The Supreme Self, but The Divine Mother IS Also The Collective Self.
At the relative and phenomenal level, where there is awareness of one’s own individual personality or ego, even Her Manifestations follow the same law, the same order that is seen in the rest of the universe. The Various Emanations of The Divine Mother Combine both the Transcendental and Phenomenal levels of truth to varying degrees. It may not be inappropriate to suggest that while ultimately at the transcendental level The Divine Mother Is The Supreme Self or Brahman, In Her Manifestations As Other Goddesses The Divine Mother Is Also The Transcendental In The Phenomenal. In other words The Divine Mother IS The Transcendental, The Divine Mother IS the Phenomenal and The Divine Mother IS also The Transcendental in the Phenomenal. This is the uniqueness of the Shakta world-view.
Reference: The Glory of the Goddess-“Devi Mahatmyam”, Dr. Satya Prakash Choudhary