Taking to Instagram on Tuesday, the Big Little Lies actress shared a sweet selfie with her mum Janelle.
"Happy Birthday Mumma - you are SO SO LOVED!! xx"," she captioned the post with three large love hearts.
The 51-year-old mother-of-four added a second photo to the post which she revealed was taken during Janelle's time as a nurse.
"P.S. I love this photo from her nursing days at the Royal Prince Alfred Hospital and Royal Hospital for Women, Sydney," she wrote.
Despite her glittering Hollywood career, Nicole shares her mother's passion for helping the sick.
She recently spent a day visiting patients at Sydney's Children's Hospital with husband Keith Urban.