But the girl's clearly considerably overweight around her middle; so it's entirely plausible that she could have had a breast reduction whilst slim overall, then when she gained weight her tits grew commensurately once more...
Yeah, that's not how those things work lol. The only way they'd "grow back" is if she just stacked on a ton of weight OR she just got implants and you're one of those goons who can't tell implants from natural boobs.