“My Big Fat Greek Wedding” writer-actress Nia Vardalos spoke at Horizons for Homeless Children’s annual Women’s Breakfast, held Wednesday at Westin Copley Place. Vardalos, who recently wrote a book, “Instant Mom,” about adopting a 3-year-old girl, spoke movingly about Horizons’ efforts to help homeless kids. . . . Pats cornerback Kyle Arrington hosted a karaoke night at the Kowloon and the event benefiting Dance Etc. drew a crowd. Former Pats tight end Jermaine Wiggins emceed, getting things going with a rendition of Rick James’s “Super Freak.” Also joining in were Pats players Joe Vellano and A.J. Francis. . . . Rapper Sean Paul was spotted at Red Lantern this week.