At the weekend, the Derry native performed as part of the Bongo’s Bingo tour in Liverpool.
She is also scheduled to perform at various shows in England as part of the tour.
As well as playing her own single All That I Know on Saturday night, Nadine also performed Girls Aloud hit Love Machine.
Nadine’s performance comes days after band mate Cheryl Cole announced she was pulling out of a headline slot at Birmingham Pride in order to process her grief.
In a post on Instagram, she said: “Saying goodbye to somebody you spent such a massive piece of your life with is like nothing else.
“My heart is heavy. Grief is such a harsh experience and an absolute rollercoaster of emotions, questions without answers and pain without resolve. So tumultuous and constant.”
Sarah Harding passed away on September 5 after revealing she had been diagnosed with advanced stage breast cancer in August 2020.
Her death comes 20 years after she and Nadine first met on Pop Stars: The Rivals, where Girls Aloud was created.
Nadine has since told of her absolute devastation at her passing.
The pair had remained close over the years, even after Girls Aloud split up in 2013.
Nadine said: “Sarah was the life and soul of the band. We laughed together, performed together, and grew together.“Sarah was so much fun and a great friend, always. I’m truly devastated that Sarah has passed. She went through the last year with grace, courage, and immense bravery and I already miss her so much.
“I have treasured memories of so many great times together that I will cherish always. May she rest in peace, my forever beautiful friend.”