Pretty sure Ashley has natural breasts. They look natural and I don't see any scars. There might be some on her areola but there are plenty of pictures where you can see her nips/areolas and they look normal, no scar tissue. You can get a breast reduction even with natural tits.
Ashley Tervort has implants. She admitted to it on her Youtube channel years ago. After getting the implants her weight dropped drastically. At one point it seemed she was anorexic. She was always dieting despite already being very thin. The anorexia was probably a result of her modeling career. When she quit modeling, she recovered. She gained the weight back and a lot of fat cells went to her chest. I don’t know why or how but her tits got way way bigger. I wish I still had the pics from her insta, because her weight fluctuations were well documented on there. In conclusion, she does have implants, but most of the size is natural. That is way they look, move, and probably feel natural.