The couple announced this month they have separated after 25 years of marriage. They are the parents of four children together.
Schwarzenegger, a film star and former California governor, confirmed this week he fathered a son during an affair with a household employee more than a decade ago.
E! News said Shriver retained the services of Laura Wasser -- who has represented Angelina Jolie, Britney Spears, Christina Aguilera and Nick Lachey in their high-profile divorces -- before this week's news of Schwarzenegger's infidelity broke.