Playboy is worth a try, but her shape is not really in line with their taste. I was a subscriber for years, and it's only about once every couple of years they have somebody with curves as dangerous as hers. I personally think she's hotter than 80% of the Playboy models ... she's just not their taste.
However, if she spends 2-3 (more) months in the gym to tone up a bit more (doesn't need to lose any weight, just tone up so her arms and legs look firmer and the outline of her abs is more visible), she can surely model for Victoria's Secret, Hawaiian Tropic, Maxim, Sports Illustrated, or other big names.