After graduating college, Niamh moved to New York, where she worked as the assistant designer to Brooklyn-based designer Romeo Hunte. During her time in NYC, Niamh designed for two New York Fashion Week shows and created custom designs for many A-List celebrities, including Michelle Obama, Zendaya, and Mary J Blige.

Niamh returned to Ireland in 2020 and focused on her interest in Irish design and sustainable botanical dyeing. Her attraction to this method is from the historic dyeing tradition in Ireland, which was viewed as a respected specialised field for women. Her most recent collection, "We Still Burn Her", was inspired by the vilification of women throughout history and how previous generations embraced or repressed their identities and paved the way for the future.