I've never seen Strike Witches, but I'll assume the girl in the pic you posted is Lynette. With that being said,
>>1436277 has the right idea. Thing is, how much are you focusing on her boobs? You could go with something simple as "well formed, "shapely", "perky", or even just simply "large".
If you want the reader to especially pay attention to Lynnette's breasts, then you'd do something like...
"And her breasts. Oh I could saver for them hours on end! How they perfectly balance and complete her hourglass figure, bounce with every elegant step she takes, sway with the turn of her hips, and fill her swimsuit to bursting. They're soft warm to the touch and smell of sweet honey, much like the rest of her silky skin. How tantalizing her cleavage, forming a perfect and inviting "Y". And how her delicate, supple nipples barely show upon the form fitting-garment teases the mind as much as pleasures the eyes."
You know, something to that affect as an example of detail :)
