But her life took a turn when she moved to Malaysia, where like so many migrant workers she sought a brighter future than the one on offer in her poor rice farming village.
Ambassador Le Quy Quynh said he was "very disappointed" with the decision.
Vietnam's ministers of justice and foreign affairs are communicating with their Malaysian counterparts to secure his client's release, Mr Teh added.
But no such political decision appears to have been made in the case of Doan Thi Huong, prompting claims of unfairness by her lawyer Hisyam Teh Poh Teik.
Describing the decision not to withdraw the charge as "perverse", Teh accused the attorney-general of favoring one party over the other.More news: Education Minister speaks to Oldies 107.7 about cell phone ban
Kim Jong-nam, the estranged half-brother of North Korea's leader Kim Jong-un, had been waiting to board a flight from Kuala Lumpur to Macau on 13 February 2017 when two women approached him in the departure area.
The pair had always denied murder, saying they were tricked by North Korean spies into carrying out the Cold War-style killing using a highly toxic nerve agent, and believed it was a prank for a reality TV show.
They were the only people in custody after four North Korean suspects fled the country the same morning Kim was killed.
He ordered the women to mount a defense against what he said was a "well-planned conspiracy" hatched with four North Korean suspects.
No reason, however, was given by the prosecutors in the court for rejecting Huong's appeal but letting Aisyah go free.
The lawyer said he would also be submitting a representation to the Attorney-General's Chambers for the murder charge against Doan to be dropped. The decision comes a few days after another accused 27-year-old Indonesian woman, Siti Aisyah, was released on Monday.More news: Johnson & Johnson to pay $42m in baby powder cancer payout
When asked by the judge if she was unwell, Huong stood in the dock and said she suffered from tension and stress.
"I have no idea what is going on", a exhausted and pale-looking Huong, who was wrapped in a red headscarf and a coat, said through an interpreter. The defense part of the trial was to have started Monday.
After the ruling, Huong was seen sobbing as she spoke with Vietnamese embassy officials.
She was crushed when she did not get the good news she was hoping for.
Huong's stepmother Nguyen Thi Vy was so hopeful her stepdaughter would be back Thursday she bought extra cassava at the market for a celebration meal with the media that had gathered at her home since early Thursday. Conviction could carry the death penalty.
The go-ahead was given by the Malaysian attorney general, the court was informed. He urged the attorney-general to be transparent and explain why he dropped the case against Aisyah but not Huong. The witnesses said traces of VX were found on both women's clothes as well as on Huong's fingernails. Prosecutors alleged that Huong and Aisyah wiped Kim's face with the chemical before washing themselves.More news: How do Champions League, Europa draws affect Premier League title, Top Four?