As a parent and as someone who has worked for an airline for 18 years (and I'm not telling you which one !) I would never send either of my children as UM's, whether it be to ORD or to EDI.....I've seen too much of what can go wrong. Any kind of delay can complicate the process. Of course, the parent/guardian has to remain at the point of departure until the a/c is airbourne, but I've seen many of them leave as soon as the littl'un has wandered thru' security.
Is it ever worth the risk?