I hope to eat these words but I tend to agree with cc100.
I don't think she would have been included in the opening logo if they had not intended her to be a regular on the show. That just would not make sense.
So as she has not appeared since i would conclude that she has been dropped from the series or pulled out of her own accord.
After the ignorant Alex performance it wouldn't surprise me if Paul had said to her. You don't need this "Helen" pull up anchor and call it a day or something like that
She would have replied well!! "Worse things happen at sea. Then Paul would have said!!!!!! ......Oy bananarama get a grip what are you rambling on about..