Meredith was wrong for that.

Derek dies and she never thought to call HIS OWN SISTER? Then she shows up to the hospital and announces to EVERYONE that he is dead. Amelia asks her at one point “How long?” And Meredith’s response was just garbage. The whole thing came across as very selfish and inconsiderate. His sister deserved the opportunity to say goodbye to him and definitely shouldn’t have been spoken to the way she was.