In March, Nicole praised her mother on her 78th birthday, writing: 'You've loved me, guided me and taught me and I am so blessed to have you.'
During her Golden Globes acceptance speech earlier in the year, the actress also took the opportunity to praise her mother: 'My mumma was an advocate for the women's movement when I was growing up, and because of her I'm standing here.
'My achievements are her achievements. Antonia Kidman, my sister, and I say thank you Janelle Kidman for what you fought for so hard.'
Wishing Janelle a speedy recovery!