The country superstar's marriage to Robert "Mutt" Lange was ended in Switzerland this week

Credit: Fran ois Ferrand

Two years after getting her heart broken by her husband’s relationship with her best friend, Shania Twain is legally single again – which is not to say she’s back on the market.

Even as her divorce from Robert “Mutt” Lange was quietly being finalized in Switzerland, Twain, 44, was looking like a woman in love at the Swiss Red Cross Ball on May 29. Dancing the night away with Frédéric Thiébaud (the other woman’s ex-husband), 40, “she was radiantly happy,” says a source close to her.

“Her happiness certainly shone through,” says her friend Stéphane Lagonico, an ambassador for the Swiss Red Cross, who organized the ball. “They are a great addition to each other’s lives.”

With the divorce final this week, according to documents filed in Switzerland, Twain is moving on with her life. She’s prepping to shoot Why Not? With Shania Twain, her series on the Oprah Winfrey Network, amid speculation that American Idol is courting her to be a judge after her successful stint as a mentor this season.

And Thiébaud is firmly at her side through all of it. “Shania and Fred are a couple that fit together,” says a friend. Adds the source close to her: “Things are getting really serious with Fred.”

With reporting by ALEXANDRA WILLIAMS in Switzerland