Well, if she's got some "distortion" like that going on with that swimsuit, then she needs to get one that fits her a little better. Girls grow up and become voluptuous, they can't keep wearing the swimwear that they may have been able to wear at one time.
Tiny, form-fitting clothes may be nice and attractive, but if they look like they could "snap-off" or cut into you, then maybe you should try the next size up.
I'm sure she'd be very cute in something more fitting. It's not that she's fat or anything. Nor is she even slightly chubby. She's just in a bikini a tad too small for her.
