Brie took issue with a report by People magazine on her Instagram story Wednesday that contained a quote from a source that said "Brie wants to kill [John]."
"I'd never say this and I'll always love @johncena like a brother," Brie said in red lettering over the article.
"He'll always be family. My heart is hurting for he and my sister. #Truth," she continued.
Nikki announced on Twitter Sunday that her relationship with Cena was ending after six years together.
"After much contemplation and 6 years of being together Nikki Bella and John Cena announced today their decision to separate as a couple. While this decision was a difficult one, we continue to have a great deal of love and respect for one another. We ask that you respect our privacy during this time in our lives," they said in a joint statement.
Cena famously proposed to Bella in the middle of a WWE ring last year at WrestleMania 33. The former WWE power couple, along with Brie and her professional wrestling husband Daniel Bryan, were the subjects of E! reality series' Total Divas and Total Bellas.
Brie said in November that she would be Nikki's maid of honor at the planned wedding.