"She looks after my cats."
Translation:Dia merawat kucing-kucing saya.
As a broad rule, a noun will be doubled to represent a plural. However, there are a good handful of exceptions. Among other, if you use a number other than zero or 1, plural is implied and the noun does not get doubled. For an further explanation, please see: https://masteringbahasa.com/indonesian-plural-nouns and also the 'plurals' note that comes with the lessons.