How do girls' breasts develop during puberty?

Women's breasts come in many different shapes and sizes. When entering puberty in girls, from a "flat" chest, girls' breasts will gradually grow larger and become "double mountains". So how do girls' breasts develop during puberty and what should be noted?

Text - Puberty: Normal Growth and Development in Girls

Early Puberty in Girls

Breast Development During Puberty

Puberty - advice for young people in SW London :: Getting It On :: GIO

Breast Development - baby, stages, average, Definition, Description, Common problems

Breast Development During Puberty

The Horrifying Practice Of Breast Ironing In Africa, by Yewande Ade, History Street

How To Tell When Your Boobs Have Really Stopped Growing

Neonatal breast enlargement in a 4-week-old full-term girl. a A

static./s3fs-public/thumbnails/im