Indonesian to English Art/Literary Poetry & Literature early Indonesian and Malay-Chinese literature

The term 'mamacang' appears in both the earliest example of Indonesian literature 'Hikayat Siti Mariah' and the works of Kwee Tek Hoay in volume 4 of 'Kesastraan Melayu-Tionghoa dan Kebangsaan Indonesia'

One example of the use of the term 'mamacang' is as appears in the following sentence: "Nyonya-besar Van Holstein yang oleh sinyo Ari dipanggil mamacang, kelihatan sayang sekali." A 5-year-old boy is referring to his father's prospective bride's mother when he calls her 'mamacang'. She is not his real grandmother.

Would 'mamacang' be translated as 'granny', 'grandma' or some other colloquial term, rather than as 'grandmother'? I'm thinking it is similar to the BI 'nenek', which can be used to address an older woman who may not actually be one's grandmother.