the pure female element relates to the breast (or to the mother) in the sense of the baby becoming the breast (or mother), in the sense that the object is the subject. I can see no instinct drive in this.
Winnicott defines the subjective object as the condition in which the boundary between self and object collapses at the level of pure female-element being, constituting primary identity prior to any instinct-driven relating.
, Playing and Reality, 1971thesis