Kelly Rutherford is ''beside herself'' on her last day with her children.

The 'Gossip Girl' star is reportedly worried her ex-husband DANIEL GIERSCH will get sole custody of their two children - six-year-old daughter Helena and eight-year-old son Hermes - and she won't see them again.

A source told E! News: ''[She] is beside herself. Kelly truly doesn't know with certainty when she can ever see them [the children] again, as the Principality of Monaco will soon be considering her ex's petition to obtain sole custody.''

Meanwhile, the 46-year-old star recently confirmed she is unable to fight for her children in New York or California after two judges ruled that they did not have jurisdiction over the case.

She said: ''Neither California or N.Y.C. are taking jurisdiction. So who in the U.S. has jurisdiction of my America-born U.S. citizen children? They were sent there by California temporarily to accommodate Daniel's visa issue, and now California won't bring them home.

''It's just incredible as an American mom with America-born children. My forefathers fought for this country and the freedoms we enjoy.''

Kelly and Daniel divorced in 2010 and have been embroiled in a bitter custody battle since.