Estrogen may not ne must helpful , rather it may cause other issues as well. Though the size of breast depends on various factors like genetics , body mass and proportion, fat contents and physical activity etc. and hence It Is multifactorial . Similarly treatment or breast enhancement also depends on the various factor. Some of Hormonal therapy is advantageous . Breast enhancement massage oil and oral medications have also shown positive report in patiens. Considering your age it will show fast and good  results. Consult me here on practo.

Hey, oestrogen does have a proliferative effect on the breast but it may not be a very noticeable effect given how your body will utilise the drug throughout and not just at the breasts. This will also further impact your menstrual cycle and moods. Physiologically, pregnancy and lactation itself will naturally cause the breasts to enlarge but any additional intervention, your proper medical history needs to be looked into before giving any further medication related advice.

It may be helpful but it may have impact on periods as well High protein diet with nutritional supplement is advisable