AGE (V012) reports the woman's age. DHS surveys collect information about the woman's age through questions about age at last birthday and date of birth. DHS Recode Manuals provide the following information about how the AGE variable is calculated:
Current age in completed years is calculated from the century month code of the date of birth of the respondent (V011) and the century month code of the date of interview (V008). In a few cases the age in the data file will be different from that reported by the respondent when the respondent's birthday was in the month of interview, but she had not yet had her birthday. If the respondent correctly reported her age at her last birthday (and not her age at her next birthday) then the calculated age was rounded up from the reported age, to avoid inconsistencies between the age and the century month code for the birth.