I personally think that she would make a great cook, no matter what anyone on the ship might say. She's a person who excels at everything.
As a 24th Century scientist, she's probably familiar with core concepts of chemistry. Cooking actually involves a lot of chemistry-like techniques (adding this, mixing that, etc.). So I think she'd be great.
Besides, compared to Neelix's cooking, anything would be a welcome relief! (Just kidding about that.)