"I can't believe it's been two years. It seems insane that we know almost nothing more than we did the day it happened."
Despite the largest search in aviation history, the only item found from the aircraft has been a piece of its wing, which washed up on Reunion Island east of Madagascar in July last year.
Australia's Joint Agency Coordination Centre expects its 120,000sq km search for the plane would be completed by the middle of the year.
"In the absence of credible new information, governments have agreed that there will be no further expansion of the search area," it said on Wednesday.
Sara said the deadline was "very frustrating".
"They haven't found anything where they're looking and we want to know why they're not looking somewhere else. Surely they would have found something by now. It's been a long, drawn-out process and it's made things more difficult than they would otherwise."
She said there was no official plans for a memorial for her brother to mark two years since his disappearance, but she would to meet some of his friends in his home city of Christchurch, as she did last year.
"While they're still searching, there's still hope that they'll bring something home. It's very hard to have a memorial service without the person there."
The daughter of Ximin Wang, previously described him as "kind, patient and gentle; a good man". She said the way they had been treated by Malaysia Airlines was inhumane.
Phone calls were ignored, questions unanswered and families had been given terrible news in public with news cameras ready to record their grief.
"We don't want their excuses. We want them found."
Danica Weeks said she was unable to comment as she was contracted to an Australian broadcaster.
In a letter to the Herald near the first anniversary of the disappearance, she spoke of how much their children had grown.
"It is so unfair on them missing out on you and you them. But I only hope I can do that my darling; bring you home to us. I wish this every day and will never give up trying.
"We need you. Our life is not complete without you and never will be. Please come home, please come home."