Roz says she's never seen Maris before. However, this is not true. In 'The Botched Language of Cranes' from season 2, both Maris and Roz attended the hospital charity event where Frasier spoke. Although the audience did not see Maris in that episode, at one point everyone sitting at Frasier's table, including Roz, watched Maris pursue another woman at the event in the hopes of securing a seat on that woman's fund raising board. This means Roz saw Maris at least that one time.