Who is Dr. Ariane LeMinier from Possession: A Romance and what is their importance?

Dr. Ariane LeMinier is a French student of women's writings at the University of Nantes. Dr. LeMinier is working on a nearly unpublished writer named Sabine de Kercoz who wrote a few poems in the 1860s and four unpublished novels. Kercoz was a distant cousin of Christabel LaMotte. LeMinier finds a connection to LaMotte through Sabine's letters and journals, giving Roland and Maud another piece of the puzzle.