'Morning Has Broken' is a religious hymm? Geeze, I just learned something new! Seriously though, it sounds like your Dub relatives are the type that go out 'looking for persecution'. My family has attended Catholic funerals and weddings (of non-family members I might add). Those Witnesses who absolutely refuse to enter 'through Christendom's doors' are the pious, self-righteous idiots that Paul described as "super-fine Christians". In other words---they worry so much over stupid things, that they miss the meaning of Christianity altogether.
To be honest I dont know why they go to these events.............they dont take part and they leave everyone annoyed. They really arent wanted there but they are family and the non JW family don't want to cause a fuss, so they just get away with whatever they want to say and do. They make really unfeeling, uncaring comments.
Having experienced this first hand from Witnesses, my personal opinion is to tell them beforehand that if they can't respect someone else's beliefs, then don't bother showing up at all. After the horrific comments that were made to my DA'd brother by the Presiding Overseer when our other brother was killed, I will never again tolerate any smug, superior Witnesses at any family funeral. When my parents die, I will tell the elders beforehand that anyone who can't show my brother respect by saying a few kind words to him, need not bother showing up.