Thanks. I will check into that. I just assumed that because she was "mixing" airlines (BA & VA) that they wouldn't do that. At least I've got plenty of time to find out. That would be a good way to do it.
Many airlines have stopped doing it for anything that isn't bought as a through ticket (even if it's the same airline!) but BA often still does, even if it's on a voluntary basis, and particularly if they're feeling nice - as they are at the moment, pose-strike and everything. It's not guaranteed but it's definitely worth a try. They're unlikely to issue both boarding passes at Newcastle but even the luggage would be a good start - the transfer desk at Heathrow can do the rest and she'd still be able to stay airside. Good luck!
) but I thought I'd throw this bit of info in just in case it applied to any of ye.