"own motion" means: Relating to an investigation by an ombudsman or similar body which was initiated by the body itself, rather than being undertaken in respons.... This is a fairly neutral word with no inherent risk attached. There is no real cause for parental concern; it is descriptive vocabulary rather than something dangerous. If your child uses it, context will usually make the meaning clear. A brief, curious question about where they heard it is generally enough to know whether to follow up.