No post-breakup breakdown for this girl!

Newly single Selena Gomez is getting on with her life after splitting with superstar** Justin Bieber**, her boyfriend of nearly two years -- and if her ear-to-ear grin is any indication, she's doing just fine, thank you very much.

On Monday, Nov. 12, the 20-year-old "Love You Like a Love Song" singer walked the red carpet at Glamour's 22nd Annual Women of the Year Awards in New York City, where a source tells Us Weekly she looked "radiant and very happy."

Wearing a white, knee-length Giambattista Valli frock with a deep V-neck and a peplum waist, the Wizards of Waverly Place actress playfully vamped for the cameras.

"She was smiling and laughing between photos and really having a good time posing for the photographers," the witness says of the star, adding that she seemed "bubbly and upbeat" giving interviews. "She looked genuinely happy...not like she was sad or bummed out at all."

Indeed, the December cover girl could barely contain her excitement as she accepted her Woman of the Year award from the magazine.

"I am so honored to be in a room full of women that I can only aspire to be as good as they are one day," she gushed of her fellow attendees, among whom were Chelsea Clinton**, Chelsea Handler, Lena Dunham, gymnast Gabby Douglas, and screen legend Lauren Hutton. "I feel so lucky that every day I get to work with interesting people that are way smarter than me, that have taught me so much."

"I just want to share with all the girls out there -- you have a voice, you have a chance," she continued. "Just do what you love, whether it's acting or singing and just being true to who you are. The person who has taught me that is my mom. She's so strong and beautiful and has taught me everything."

This article originally appeared on Usmagazine.com: "Radiant" Selena Gomez Seems "Bubbly, Upbeat" at Bash After Justin Bieber Split