YOU SAID:
she is her sisters sick sitter
INTO JAPANESE
彼女は彼女の姉妹の病気のシッターです
BACK INTO ENGLISH
she is her sister's sick sitter
INTO JAPANESE
彼女は妹の病気のシッターです
BACK INTO ENGLISH
she is a sick sitter for her sister
INTO JAPANESE
彼女は妹の病気のシッターです
BACK INTO ENGLISH
she is the sick sitter of her sister
INTO JAPANESE
彼女は妹の病気のシッターです
BACK INTO ENGLISH
she is a sick sitter for her sister
INTO JAPANESE
彼女は妹の病気のシッターです
BACK INTO ENGLISH
she is a sick sitter for her sister
That didn't even make that much sense in English.