© PA Images / Matt Sayles
Last week, it was revealed that the former Governor of California had fathered a child with one of his house staff, an admission which is said to have been the reason for his separation from Shriver.
Despite the revelations, Shriver has remained firmly in the public eye throughout the controversy, and even made an appearance on the finale of Oprah.
"She's done nothing wrong, but even I'm surprised she has had enough courage to go out in public," the friend told PopEater.
"When this happens most women want the world to swallow them up," they continued. "They want to stay home behind closed doors, but not Maria.
"[She] refuses to hide because of what some jerk did to her."
Shriver is rumoured to have hired a divorce attorney in order to begin proceedings against her estranged husband.
