Hmmm...I hadn't heard about that particular rumor detail. Interesting, if true.If i remember correctly, and i havnt seen the trailer waiting for it to load now, It was passed down her family and it was released on Referns instructions to find The Doctor, thus the books release acts as a phone call.
And before people start screaming about Joan Redfern and her ancestor looking the same, allowing me to direct them to The Massacre of St. Bartholomew's Eve, The Enemy of the World, Black Orchid, and "Smith and Jones" for other examples of cosmic coincidences.