MH370: Mixed signals add to sense of confusion and betrayal
XU Jinghong said she could not understand why Malaysian and French authorities did not make their announcement together.
"I am very angry - so angry that my hands and feet are cold," said Ms Xu in central Beijing.
"The announcement was made without experts from France present. I don't understand how the procedure can be like this."
The announcement by Malaysian prime minister Najib Razak appeared to give the first strong physical evidence of a crash.
That could put to rest several theories that many relatives have refused to rule out, including that the plane and its passengers were hijacked and intact in some still-secret location.
However, any potential certainty was diluted by the word from Paris, where deputy prosecutor Serge Mackowiak said the "very strong conjectures" that the wing part was from Flight 370 still needed to be "confirmed by complementary analysis".
It was unclear whether the mix-up was a result of miscommunication between the two countries, or whether Malaysian officials were overeager to send out some definitive signal for relatives of the missing.
In any case, a full confirmation of the wing part was not likely to bring total closure for relatives, with the rest of the plane and the bodies still missing.
Jiang Hui, whose mother was on board, said there was still a lack of evidence to prove that the plane crashed as was announced by Malaysian officials last year.
At the time, they cited thorough analysis of the relatively limited satellite data available for the flight.
Major questions still remain, including why the plane went off course, crossed back over Malaysia and went south into the Indian Ocean.