Hi Melissa, I'm guessing you live in or near Dover, unfortunately I'm in Essex.
You could try talking to the child(ren) and telling them to go/go home in a firm voice. I often burn white sage (available from new age type shops) which I waft in to all corners of every room to cleanse the area. Don't leave it unattended as it smolders and burn it in something that won't melt. Presences like that are more annoying than harmful. They often go as quickly as they arrive. Do you have children of your own as they sometimes se out other children to play with? Have you looked into the history of your house or immediate area? That may throw up some light.
Wow Chris that made the hair on the back of my neck stand on end, what a dreadful experience.
