Jose:
The fact that she was a model for Fisher and became famous as the original "Harrison Fisher Girl" is corroborated by John Eaton ("Voyage" #8, June 1991, page 157) and Simon Mills ("The Titanic in Pictures," page 18). The one photograph of her with small flowers in her hair that seems to show up in every book or article about her, and was used on the 1912 movie poster is apparently from the December 2, 1911 "Billboard," according to an article by Frank Thompson ("Commutator," v. 21, #3, 11-97--1-98, page 12). I don't know how you would verify the sketch shown in Geller's book as being of her -- maybe there's a book on Harrison Fisher around.
Hope this helps a bit.
Mike