You might find more information if you go to a local museum in Bavaria,because in Austria and Germany every community & city has a museum or some place where they gather historically relevent books,papers,pictures and objects. There are also some gatherings of locals who are interested in history who may be able to tell you more. If you are looking for someone who is not so well-known and important in history there is still a chance that you can find something in local archives.
As AdmirerUS said, it will probably be helpful to read everything that was written about the Bavarian Queen,her family & time. Going to a big library will probably be the best way to start this search:-)
Hope you find what you are looking for!
Security is mostly a superstition. It does not exist in nature, nor do the children of men as a whole experience it.
Avoiding danger in the long run is no safer than outright exposure.
Life is either a daring adventure,or nothing. Helen Keller