She's, strictly speaking, not vegetarian, but some call people like her pesco/pollo vegetarians. When someone says vegetarian (I'm vegetarian myself), he/she is referring to lacto-ovo-vegetarian, which means you don't consume beef, pork, poultry, fish, and seafood, but do eat dairy products. Vegans, on the other hand, do not eat dairy products.
I don't know. Maybe supermodels tend to use the term 'vegetarian' in a loose sense--like Heide Klum claiming to be vegetarian on the Tonight Show while admitting that she's from Germany so she loves and does eat sausage.