I think you mean wired and unwired bras
Wired bras have a U shaped piece of wire under the breast to hel maintain a shape, unwired are soft only.
It all comes down to the shape and size of your girl as to what will fit best. If her breasts are very soft and move naturally then a wired bra would be a good choice.
Just make sure the strap size is right for her under-bust measurement, and the cup size is large enough for her boobs or the strap will be pulled away from her body.
https://www.anita.com/en/products/fi...ulator-uk.html
K