(Cover) - EN Showbiz - Justin Theroux has been a "hero" to Jennifer Aniston following her mother's stroke.

The Hollywood pair met while shooting movie Wanderlust and went public with their romance earlier this year.

Jennifer has been leaning on her beau as she deals with her mother's health problems.

"[Justin's] been a hero. He's driving Jen to and from the hospital when they're in LA. He's sitting in the waiting room or circling the block in her car until she's done He's there for her 24/7," a source told Look magazine.

Jennifer is reportedly by her mom's side whenever she can be. The American actress is joined by Justin on most occasions, and he has pledged his support to his concerned partner.

"Justin's trying to reassure Jen that Nancy needs her rest, and won't mind if she isn't there all the time but she's still trying to visit her every evening," the source continued.

"There were work commitments in NYC I think she struggled to get out of. But if Nancy gets any worse, which she could, Jen's prepared to drop everything for a round-the-clock vigil. Justin will want to be there for her then, too." (C) Cover Media