"I'm looking forward to working alongside Andrea, but this decision wasn't an easy one as I've been with Assets for five years," she said.
"This is the beginning of a new chapter in my career."
And new agent Andrea said she was "delighted" to be representing Nadia, who is now with the same agency as Rosanna Davison, Pippa O'Connor and Rozanna Purcell.
Ambitious Nadia has just finished her first stint in the Christmas panto at the Tivoli after revealing how she planned to do more performing this year.
A trained singer and dancer, she was one of the finalists in Louis Walsh's hunt for a girlband and almost made it into Wonderland.
She recently spread her wings into TV and appeared in Celebrity Salon, as well as shooting a music video for British rapper Luke Bingham.
She has been approached by a number of talent agencies in London after indicating she would consider moving to the UK to further her career.