Polish names don’t typically use patronymics. However, when surnames were first used in Poland, some surnames were based on patronymics. The patronymic was then passed down to future generations as a surname.

Zygmuntowicz was originally a patronymic from the name Zygmunt. Napierkowski is not a patronymic.

Since I’ve had no luck finding my grandfather’s Birth and Baptismal Record or my great-grandparents’ Marriage Record, I think it might be worthwhile to see if there is a Zygmunt Napierkowski in the Szwelice parish records. Who knows? The search won’t take long and I might just find something!

I’m not familiar with Polish names, but with Russian names a woman might be known by her given name, her patronimic, and her last name. Sometimes only the given and patronymic were used. Perhaps this is what’s happening with your Polish records?

I hadn’t thought of the possibility that Ksawera might have been raised or adopted by another family, but that’s an excellent hypothesis. In the past, I’ve found that my ancestors usually didn’t leave blatantly incorrect records, so I’ve been loathe to speculate that my grandfather just wrote the wrong name for his mother’s maiden name on his Social Security Application. I’ll keep your hypothesis in mind as I continue to search for my grandfather’s Birth and Baptismal Record and my great-grandparents’ Marriage Record.

Here’s the scenariao: Ksawera’s parents had one surname (say Zygmuntowicz) which she had too when she was born. Then her parents died when she was young and she was raised by one of her godparents who had the second surname (say Napierkowski). They weren’t fussy about legally adopting orphaned children in the old days back in Poland, so I’m told. It was actually common for children to assume the surname of the family that took them in and raised them, or use both surnames interchangeably. This was explained to me by someone doing some research for me in Poland. It happens to have been true in the case of someone on my family tree who used 2 surnames interchangably. It could be the case here as well.