Did some more looking around and found this article(I've attached) in the 4/6/1911 Hudson Register at www.fultonhistory.com
that might explain what happened to Dorothy and Frederick. I know they say the daughter that died was Jennie, but that could just be bad reporting. Looking at census records shows Dorothy died sometime between 1910 and 1915. Have you checked with the cemetery where Bessie & Jane are to see if they have records for Dorothy? You would think if Bessie was that affected by her death she would want to be buried near her.