From Wiktionary, the free dictionary
bà (“woman”) + ấy (“that”).
bà ấy
- (Northern Vietnam) she (woman of higher social status, e.g., older)
- Synonyms: bà nớ (Central Vietnam), bả (Southern Vietnam)
- chị ấy (young girl and older than the speaker)
- cô ấy (young girl or woman)
- nó