A divorce between Jesse James and Sandra Bullock is reportedly imminent due to his alleged infidelity, however the Oscar-winning actress is concerned about how it will impact her three step-children with the reality TV star.

"[The allegations have] broken her heart, and they will divorce," a source told Fox News in a Wednesday report.

"She is trying to pick her way through the mess and all the stress of knowing his three children will be hurt no matter what happens. The kids are what is holding her back from filing for the divorce immediately. It's been tough and she wants to find a balance for them - they deserve some stability, even through the divorce."

Bullock reportedly started to prepare divorce papers to end her four-year marriage to the former Jesse James is a Dead Man and Monster Garage star earlier this month after allegations surfaced that he had affairs with several other women.

However James, who also competed on The Celebrity Apprentice's 2009 edition, is currently at Arizona's Sierra Tucson Treatment Center for a 45-day sex addiction treatment program and Bullock "is trying to tread lightly," according to the source.

"Sandra is doing this on her own timeline and refuses to budge or give in to people who say she should divorce him immediately," the source explained to Fox News.

"Jesse and his children are her family and in some ways always will be. She is not ready to scrap it all as fast as possible. She's taken some time off and plans to stay out of the spotlight. Sandra and Jesse will talk again, but divorce will happen. She has a master plan."

Last month, James was accused of carrying out an 11-month affair with tattoo model Michelle "Bombshell" McGee while Bullock was in Atlanta filming The Blind Side -- for which recently won the Oscar for Best Actress.

Several additional women then also made similar claims, resulting in James reportedly admitting to Bullock -- whom he wed in July 2005 -- that he had affairs with seven different women before he left for treatment.

"Sandra got to be with a side of Jesse that he rarely gave to anyone else and now she's seeing what everyone else always saw," the source told Fox News.

"They were truly from different worlds and Sandra sees that Jesse lived a double life with her. She's so level-headed and grounded and that is what is getting her through this."