This is an old post, but the original poster may still be interested in the matter. My mother's mother was a born Ladda. She grew up in Johannisburg, Eastern Prussia; this part of the family fled from the Sowjet troops in February 1945 - and subsequently settled in Soltau, Lower Saxony. My grandmother died in January 2009 aged 95. If you are interested to learn more, please let me know.