Thanks for the reply. No, the flight hasn't yet been cancelled which is the problem. Once its cancelled she's sorted but as it's going in a couple of hours it doesn't look like it's going to be. She'll try them again this morning otherwise I guess she will try on her insurance.
My sister was due to travel to Denmark tomorrow with Norwegian. Denmark has just closed its borders so she clearly can't go. Norwegian have refused to refund or rebook her for free even though she won't be allowed in. Good customer service!