I have found some more references for this family:
Prince Gregorios Ypsilanti m. Baroness Helena Sina de Hodos5 children, including 3 sons: Constantine, Emmanuel, Theodore, and two daughters,
Princess Chariclee Ypsilanti (1863-1912) m. (1882) Prince Philipp Ernest of Hohenlohe-Schillingfurst
Princess Iphigenie Ypsilanti (1869-1943) m. (1888) Count Albert zu Pappenheim
I think the family lived in Paris at one time, as the girls are listed as being born there.
Here is a link to a genealogy site about the princely Dadiani family, which the mother (Baroness Helena) was descended from. Page down about three quarters of the way and you will find this family.
http://www.4dw.net/royalark/Georgia/dadan3.htm