How can I respectfully tell my (very intelligent) intern that she sounds like a valley girl?

She’s a college senior, about to graduate. Smart, entrepreneurial, eager, does a great job. however, every sentence is peppered with “like” or “totally” and it makes her sound 15 years old. I’ve already been working with her for 4 months so I feel like it’s odd to bring it up now, since she’s been dealing with clients for a while already. But I“m recommending her for a job within our organization, and before she goes to interview with that supervisor, I want to give her some advice. How can I tactfully give her this feedback?