Sorry I have no idea what the story is on the luggage, I'm presuming it went missing, if so then it's the airline responsibility to get it to you and if they are dragging their heels then get your insurance company involved. (Presuming she informed them at the time that they may be making a possible claim).
but this is Sue, and she's hardly known for her honesty! it wouldn't surprise me if she is criticising the airline and making a huge drama about the stress it's causing her all over SM for attention, whinging that she ahs no idea how she is going to get her luggage back because the airline refuse to send it back to the UK when in reality, she has requested the suitcases stay in NY because she has already booked flights to go there again, undoubtedly demanding a huge discount on tickets for the inconvenience caused, and will then announce their trip to NY as a spontaneous decision or a valentine's surprise from Nowull - when it's been planned the whole time, with collecting their luggage to justify another expensive trip to NY.
she is gonna regret it when it comes back to bite her on the arse when the airline don't take too kindly to her lying about them and spreading rumours all over the Internet about how they have refused to return her luggage when, realistically, that is incredibly unlikely.