Cena and Nikki announced they were separated just weeks before they were due to marry after getting engaged last year at Wrestlemania.

Brie had previously attacked reports she wanted to “kill” Cena after the split.

And now the 34-year-old has given her first interview about her sister’s earth-shattering break-up, telling fans "personal" details will soon emerge.

Nikki has not yet said anything more since announcing the separation on her Instagram.

Cena has simply responded by posting cryptic tweets alluding to the “burden of shame” and “hardship, loss and humility”.

Speaking to PEOPLE, Brie said: “She’s good, they call her fearless Nikki for a reason. She always puts on that brave face.

“My sister has more strength than any other woman I know, especially Wonder Woman. She’s bigger than that.”

Brie and Nikki – known on screen as the Bella Twins – became a WWE brand juggernaut along with Cena, taking the starring roles in reality shows Total Divas and Total Bellas.

She revealed fans will get to know some about the final days of Cena and Nikki’s relationship in the new season of Total Bellas.

Brie said: “I really had to take a step back and allow it and that was really hard on me because it’s my twin. I want to protect her from everything.”

She added: “I have to give a lot of credit to John and Nicole. They really opened up their lives and they really wanted to close the curtain and be like this is it, we’re done.

“My sister is really great with her fans in a way where she lets them connect with her."

The WWE star said “personal conversations” will be revealed the fans on the show.

Nikki and Cena had been together for six years and were due to get married in next month in Mexico.

The couple’s statement suggested the separation was amicable, but sources have claimed Nikki is “heartbroken”.

It is alleged Cena, a 16-time world champion, got cold feet in the lead-up to the wedding.

He had previously been vocal about his reluctance to get married when appears on Total Divas and Total Bellas.

Brie is married to fellow WWE star Daniel Bryan, and the couple have a daughter tougher named Birdie.

Cena and Nikki had been together since 2012 after the WWE legend had separated form his previous wife.

He proposed to her at WrestleMania after winning a mixed tag-team match against The Miz and Maryse.

Struggles in their relationship had also been made public on reality TV, such as Cena making Nikki sign a 75-page contract before moving into his luxurious mansion in Florida.