The US Census and the Social Security Death Index contains the following information:
Iva L. (Winney) Johnson b. 4 feb 1906 NY (probably Buffalo)d. aug 1973 Buffalo
living with mother, grandmother and brothers in Buffalo in 1920 Mother: Leonore (Gilbert) Winney b. Jan 1857 canada m. 1900 d. jul 1969 Alden, Erie Co., NY Brothers: Harold E. Winney b. 10 jun 1903 NY, d. Mar 1974 Buffalo Ralph K. Winney b. 9 nov 1907 NY, d. oct 1970 Grandmother: Mary L. Gilbert b. jan 1857 canada m. 1878 d. aft 1930, probably Buffalo
Mary also had son, Charles A. Gilbert b. sep 1880 canada
Ralph K. Winney is living with grandmother Mary Gilbert in Buffalo in 1930
If you have not already do so, I would try to obtain death certificates on members of Winney family.