You were talking mainly about anatomy and problems with breast suspension , if you want focus ont the picture Lets talk about it:
You complained that she seems to not wear Bra , but you have overlook something : If you look closely to the Picture , that tight suit its acting like one .
On her Broadside and Shoulders you can clearly see black joint points with a more sturdy looking than the rest of the Suit , they also seems to have buttons attached . Those points are obviously restraining the suit in the Same points a Bra would . She also have a collar of the same material that completly tights around the neck , wich Holds the breast from above. All those elements is what creates that Push-up effect on her breasts.
For the Practical aspect of her tight suit , all her Missions she does them inside a Mechanical armor that is meant to imitate a human body as much as possible while fitting a real human inside of it . The less Bulky is the human inside the smaller and more Practical the Armor can be , that's why she wears a Suit that is Thin as a Layer of SKin . That explains why she have the nipples so marked.
For the practical aspect of having good sized breasts , you can consult Health experts , the Suspensory ligaments you are talking about can be Strengthen , check it yourself
www.livestrong.com/article/428…That is for regular people with a soft exercise routine , a highly trained woman can have those ligaments strong enough so the breast bounce is not a Practical problem , a different thing is that they find it embarrasing.