Kelly Rutherford with Hermes and Helena  By Emily Strohm and Dana Kennedy  08/20/2015 AT 02:45 PM EDT  Three years have passed since a judge ordered  's children to move to Monaco with their father, German businessman  , but Hermes, 8, and Helena, 6, are still  "They're beautiful children," a former teacher at their exclusive school tells PEOPLE. "They look like Gap kids, but they blend in here, too. They're both reserved."  When it comes to their education, no expense is spared: "It's a very exclusive," adds a 41-year-old mother whose children attended the same school. "Kids come from all over the world and it follows a British curriculum. Some kids speak as many as five languages so school can be challenging for them. It's good academically but very elite."  As far as their home life goes, the family makes privacy a priority by living behind a fortress-like wall made up of fencing and high shrubbery in a big, modern compound with a swimming pool.  "Uniformed city police patrol the area on bicycles," adds a source. "Every home is similar. Hard to see, hidden behind walls, grand fences, trees and shrubs."  While a court order states that the children must live with their father  in Monaco, Rutherford – who has been vocal through her contentious, six-year  with Giersch – refuses to give up hope that one day she will be permanently reunited with her children.  "This whole time, what I've had to do is take an overall situation that's so bizarre and try to keep my kids healthy. I have to keep knowing if I'm okay, they're going to be okay. I don't want them to be fearful," she  . "My children ask me all the time if I am still fighting for them. ... I always tell them the day will never come when I say no."
The former Gossip Girl star's children are still adjusting to the elite, walled-in world of their father's Monaco estate