Touted as ''the largest children's festival in the United States,'' and with an expected total attendance of 50,000 (most of those kids), the Houston Children's Festival deserves its notation as one of ''The World's 300 Unmissable Events'' from Frommer’s Travel Guide. We just named it one of Houston's Top 10 Festivals. Highlights of this year's event include appearances by Victoria Justice, star of Nickelodeon's insanely popular Victorious series, and Laura Marano from the Disney Channel's Austin and Ally show. Of the more nonhuman variety, attendees can also ''meet'' Dora the Explorer and Sid the Science Kid. Overall, the festival will have five stages of entertainment and music and 300 activities, including crafts, games (most included with admission), sports and rides, as well as food and beverages. Proceeds benefit Child Advocates, Inc. for abused and neglected children.