Possible maiden name due to a lead. A descendant of Frank is mentioned to have a godfather by the name of Joseph Goralski and Joseph is mentioned to be related to Frank, Sr.
After looking up Joseph Goralski in the Milwaukee US Census records, he is shown living with his wife and in-laws. His in-laws are August & Anna Gwiazdowski. Using this information, he is found with these individuals in a Philadelphia passenger list in December 1892. In the notes for this group of people it says, "Visitors Nephew Franz Zaleski at 902 Pulaski St" [sic] which would make August Frank's uncle and GWIAZDOWSKI his mother's maiden name.
All info points to a correct match, but more info is needed. Pulaski street is very near to where Frank and his family lived (northeast Milwaukee/Riverwest area.)