The 84-year-old actress was at home discussing Carrie's funeral plans with her son Todd Fisher in Beverly Hills when she suffered what TMZ has branded a 'medical emergency'.
It happened just after 1pm local time and emergency services were called to Todd's house.
An ambulance was sent to take Debbie to an emergency room nearby, where she'll be given treatment.
After news of Carrie's death broke on Tuesday 27th December, mum Debbie took to social media to thank fans for their kind words.
"Thank you to everyone who has embraced the gifts and talents of my beloved and amazing daughter," she wrote on Facebook.
"I am grateful for your thoughts and prayers that are now guiding her to her next stop. Love Carries Mother."