Genealogy / Any Polish Tatars here? [95]

I am still researching my background concerning Lipka tatars. My grandmother on my father's side maiden name was Lipka. Her parents had a horse ranch (with well bred horses) in what is now Poland during WWII - at that time the location was eastern Germany. At the end of the war the Russians took all. She later changed her last name to Lepter when she came to USA but her marriage certificate from Connecticut shows Lipka as last name in one part of document and Lepter in another. Could there have been a reason for changing her last name (political/cultural)?

Thanks