Twain assured her fans in a personal letter posted on her Web site that she was "alive and well" following her 2008 split from Lange, who was reportedly having an affair with Twain's best friend, Marie-Anne Thiebaud, People.com reported Friday.
"I feel very alive and well, ready to take on the gift of another year," Twain, 44, said.
Since her split from Lange, Twain has been seen out with Thiebaud's ex-husband, Frederic Thiebaud, prompting rumors of a possible relationship between the two.
Twain said Frederic Thiebaud has been a "constant companion" for her and her 8-year-old son Eja.
"(He) has been the most constant companion and support for both Eja and I. And having gone through the suffering of his family splitting apart at the same time and under the same extreme circumstances, he understands me better than anyone," Twain said online.
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