Ricky was a character present in all of Tom Paris' holoprograms.
She was based on Richenda Masterson, the founder of the Interplanetary Art Exchange program, whom Paris met in the 2360s at Chez Sandrine in Paris. The two became "romantically involved" for a time, in that she loved him but he did not love her. (VOY short story: "A Night at Sandrine's", VOY episode: "The Cloud")