I have read & reread the letter and unfortunately I cannot make any improvements on your transcription, the only thing I can offer is that her 'D' is always made either capitalized or with a large loop and some of the illegable words appear to contain a D.

I first read this post because of the Fellner name, hoping for some connection to my Hungarian Gfelner family. Do you have any information that your family may have changed the spelling of their name? My 2nd great grandmother was Elizabeth Gfelner b. 1853, an Austrian/Hungarian aristocrat. I have found a George/Gyorgy Gfelner b. 1858 who I believe to be her brother. (Elizabeth's daughter Betty married a 'cousin' Jakob Gfelner, the son of George Gfelner).

I'm hoping someone can help me with a connection and provide more information.