I am looking for ancestors and family members of my former wife's Great Grandmother.

Rose Polizzi (8 Dec 1894/1895 - 1971) came to America in about 1919 and was born in Italy. In 1930, she was married in about 1920 to Salvatore "Sam" Torchia (26 Oct 1889-7 Dec 1957)and was living in LaSalle, Illinois. Salvatore was from the Parco, Italy area (today known as the island of Sicily). Both Sam and Rose are buried in the St. Vincent's Cemetery in LaSalle, Illinois.

I have very little else to go on. Family members have helped to identify the following information:

Father: Unknown
Mother: Mertily
Siblings: Joe (1897-?), Frank, Rosale, Sam

Joe married Petrina (a 1903-?) and they had 8 children:
Mary, Josie (1927-), Carmolina (1928-?), Joe (1929-?), Nino (a 1936-?), Peter (a 1940-?), Isabelle (a 1941-?) and James (1944-?)

If anyone can make a connection, please help me identify her parentage.