Going BOS-JFK on B6, then JFK-MXP on EK and will be traveling with my wifes parents and meeting her down at JFK. They are capable, but I would like to make things as smooth as possible. Not sure if its possible to book luggage cross-carrier like that as I have never done it. Is this something that's normally done AND is reliable? It would suck mightily for us to land in Milan only to discover my MILs bags are still sitting at JFK. I know my other option is simply to grab everything at baggage claim, and move to the international terminal and recheck, but thats a pain in the ... for them.

Thoughts or suggestions?

Thanks!