"Somewhere there was a notation that Polish names which ended in A indicated a female and those which ended in I indicated a male. If so, you may wish to also check for STEMPKOWSKI vice STEMPKOWSKA ..."
The feminine ending indicates an unmarried girl, and it was also used to indicate a widow. So a Mrs. Stempkowski may become known as Mrs. Stempkowska within the Polish community. You can also see this on some gravestones in Milwaukee cemeteries. It is important to check both spellings for someone who would be at either end of the age spectrum.