No, its origins are from Hebrew (Jewish) roots.
I really don't know what it means in Welsh, but the origin of the name Sarah is Hebrew and the meaning is "princess", sometimes qualified as Sarai, "my princess", as in the case of Abraham (compare rabbi, "my teacher"). The proper spelling for in welsh is "Sara"
Enw. That is how you say name in Welsh.
It doesn't appear to be a Welsh name and would not have a Welsh version.
Freddy Welsh's birth name is Fred A. Welsh.
Mikey Welsh's birth name is Michael Welsh.
Ronnie Welsh's birth name is Walter Ronald Welsh.
Susan Welsh's birth name is Welsh, Susan E..
The Welsh word for "Welsh" is Cymraeg :)
Sara Amato's birth name is Sara Amato.
Sara Sagal's birth name is Sara Zwilling.
Sara Saidy's birth name is Sara Saidy.
Sara Biala's birth name is Sara Bialablotcky.