Hello doctors. is it true that if a female has had large breasts early in life, then her breasts start to sag in her early30s or later in life?

From the beginning: Big breasts start to sag from the very beginning due to gravity (but we do need our gravity). The amount of sagging varies from person to person, depending on how "strong" the internal connective tissues of one's breasts and chest area are. Some sag a little; some sag a lot. Because bodily features are often familial, looking at one's older female relatives may offer a window to the future.