"Das Mädchen hat Katzen."
Translation:The girl has cats.
I think "the girl owns cats" should be okay. I know it's not direct word-for-word correct, but means the same thing.
I put "the girls have cats" - I thought the plural of "Mädchen" was "Mädchen"?
Also, note that the verb was in er/sie/es form. "Hat", not "haben". So there's another clue it couldn't have been "The girls".