The origin of White Tara is the same as mentioned about the Green Tara.

The femal Bodhisattva White Tara is seated in full Vajra posture and her left hand which is poised at the heart holds the stem of a lotus that opens into blossom beside her left shoulder. Her right hand is in the Varada mudra symbolizing supreme generosity. She is seated upright on an moon disc. She is wearing all sorts of precious ornaments and looks beautiful maiden of sixteen years of age. Amitabha Buddha image sits upon the head as a crown. The practice of white Tara is basically performed in order to prolong life as well as for healing purpose. White Tara is generally portrayed as seated, dressed and crowned like a Boddhisattva with an extra eye on her forehead, she has seven eyes (also on her palms and soles).