Are you positive that she died? Below are Peter Lorre's family members and as you can see on the list, Catharine Lorre's birthdate is shown only, no date of death is listed. At least not anywhere I have looked.
Father: Alois Lorre
Mother: Elvira Lorre
Wife: Celia Lovsky (m. 1934, div. 13-Mar-1945)
Wife: Kaaren Verne (m. 25-May-1945, div. 1950)
Daughter: Catharine Lorre (b. 1950)
Wife: Annemarie Brenning (m. 21-Jul-1953, until his death, one child)
I'll keep looking and if I find something I'll send it your way.