It is more likely to be one of the above explainations we've all offered, but since we haven't been given a context, I thought I'd outline the third (less likely) possibility, for completeness (also in case anyone seriously thought I was suggesting children could be being chartered :-)). It is possible (although less likely) that the parents are actually chartering or hiring transport (eg: an aircraft, ship or boat) either accompanying their children themselves (eg: on holiday or for medical treatment abroad)or sending them off with others (eg: as in a school trip for instance, or again for medical treatment abroad). Separation from their children or other problems that might arise in whatever situation it was, could give rise to emotional problems that needed handling.
As said, I think the other suggestions we've made are more likely (without context), but as we don't know it would be a pity to leave it out......