I think she was killed as a lesson to be learnt by the other staff working at this hospital.. the truth is kate is carrying this royal child, which has illuminati bloodline.. there is a high chance this child is not even human... so thats why i think they killed this nurse for just a hoax phone call... because if other staff at the hospital will find out any controversial information about this baby they wil surely keep their mouth shut whatevar happens... i think the message we get from this is indirectly very clear!!