The "Gossip Girl" alum was expected in family court to argue that her son Hermes, 8, and daughter Helena, 6, should live primarily with her in the United States, where they were born and maintain citizenship, as opposed to with her ex-husband, German businessman Daniel Giersch, in France and Monaco.
Earlier today, the 46-year-old actress posted photos on Instagram of her snuggling with her kids.
Skipping the captions on the photos, she instead posted a poem by E.E. Cummings.
She also shared a list written in child-like scrawl by daughter Helena.
Ordered last month by a Manhattan Supreme Court judge to return the children to their father after spending the summer with them in this country, Rutherford was "hoping for the best" at today's court hearing, her U.S. lawyer Wendy Murphy, who is not representing her abroad, told ABC News in a statement.
"Kelly trusts her Monaco legal team and feels that the Monaco judge treated her with respect when she was there last June. She believes the judge will again treat her with respect on September 3," Murphy said.
"Kelly is praying that the judge in Monaco does the right thing on September 3, and sends the children home to America," Murphy added.
In 2012, a California judge sent the children to live in France with Giersch, whose U.S. visa had been revoked. Though Rutherford has been trying to bring the children back to the U.S. for years, neither the California nor the New York court systems claim to have jurisdiction in the case.
The Monaco court will likely decide whether it has jurisdiction to decide custody rights, while taking up Giersch's motion to be granted sole custody and Rutherford's objection to calling the children are "habitual residents" of Monaco, Murphy said.