Gender distinctions in the Standard Chinese written forms 他 (he), 她 (she), 它 (it) are indeed a recent introduction. In Cantonese there's a single character f

Gender distinctions in the Standard Chinese written forms 他 (he), 她 (she), 它 (it) are indeed a recent introduction. In Cantonese there's a single character for he, she, or it (佢, pronounced keúih). This is a different word entirely from Mandarin tā, not a different pronunciation of the same word like 雞 being pronounced jī in Mandarin or gāi in Cantonese. Because, as you pointed out, there's no mutual intelligibility, Cantonese and Mandarin are considered by linguists to be separate languages.