I was prepared for when my eldest DD (now Yr7 but very young for her year) realised about Father Christmas and knew she would play along for her younger brother, but am now in the opposite situation where she still believes in him but my DS (yr4) doesn't. Should I ask him to keep quiet or do you think it is kindest to tell her now - as I am also bit concerned she may be teased if she starts talking about FC in front of some of the more mature girls in her year?