Kady is not a correct spelling...
The 1930 census shows them living at Gary IN, Steve's arrival year is shown as 1905 .. indication is he was a Naturalized Citizen at this point... while Katie arr 1920...
Croatian for Steve would be Stjepan, Stipe, Stipan or Stefan Katie would be Katarina, Kata or Katica
Steve's 1917 WW I Draft Registration shows his b'date as
June 18, 1886
BUT .... ! Then one can only guess these are your KUCANs as you did not mention if they lived in Croatia, America, South America, Australia, etc...
Robert Jerin
Croatian Heritage Museum
Cleveland Ohio