"I am grateful for my entire family, my longtime girlfriend, Amber, and friends as we prepare to celebrate a glorious new year together," Roberts wrote in a posting Sunday.
The couple have been together for 10 years since they met through mutual friends, People.com said.
Roberts is a breast cancer survivor who was treated for myelodysplastic syndrome, a rare blood disorder, this year.
In her posting, Roberts thanks Laign, her family and friends for their love and support through her health crises.
Celebrity Breakups and divorces of 2014 [PHOTOS]