In the Facebook post, Roberts remembers the one-year anniversary of reaching 100 days after her bone marrow transplant.
She thanked her supporters saying, "I am grateful for my entire family, my long time girlfriend, Amber, and friends as we prepare to celebrate a glorious New Year together."
The post is the first time she's made public mention of her girlfriend, Amber Laing, a massage therapist from the San Francisco Bay Area. Roberts' post was confirmed by ABC News spokeswoman Heather Riley.
ABC News' Jeffrey W. Schneider released a statement Sunday:
"We love Robin and Amber, who we have all known for a long time. We were so touched by Robin's Facebook message today and so thankful for all the incredible support she has in her life."
The couple has been together for a decade.
The Associated Press contributed to this report.