On social media, Ukraine's first lady emerges as a fervent supporter of her country.

 (CNN)Ukraine's first lady, Olena Zelenska, wrote an open letter to the world's media on Tuesday, documenting what she called "mass murder of Ukrainian civilians."

Zelenska has been using social media to highlight the problems of her country in recent weeks, but none has been as blunt as her most recent post, which closes with the rallying cry: "We will triumph. Because of our comradeship. Love for Ukraine can only be achieved via unity. Ukraine is to be praised!"

As her husband, President Volodymyr Zelensky, has emerged as the face of Ukrainian defiance against Russia's invasion, Zelenska has grown more vocal online in order to support him and raise international awareness of their country's situation.

On February 24, when Russia invaded Ukraine for the first time, Zelensky declared

For security reasons, the whereabouts of his wife and two children remain unknown. Nonetheless, Zelenska has been active on social media, motivating her people and supporting resistance to Russian forces while gathering international support. She has 2.4 million Instagram followers.

The 44-year-old sent the open letter on her different social media channels and on the President's official website on Tuesday in response to the "overwhelming amount of media outlets from across the world" who had requested an interview with her.

She opened the fervent letter, titled "I testify," by recounting the events of February 24.

She wrote, "Tanks crossed the Ukrainian border, planes entered our airspace, and missile launchers ringed our cities."

"Despite assurances from Kremlin-backed media channels, this is, in fact, the mass slaughter of Ukrainian citizens."

Zelenska emphasized the "terrifying and terrible" child deaths, as well as the tragedy of newborns delivered in bomb shelters and "flooded" roadways with refugees.

Zelenska was born in February 1978 and met her future husband at the Kryvyi Rih Gymnasium No95 high school in Kryvyi Rih, the southern Ukrainian city where they both grew up, according to the website of the Ukrainian Women's Congress, a public platform that advocates for gender equality in government and wider Ukrainian society. Her website biography states that she went on to the Kryvyi Rih Economic Institute and majored in architecture, graduating in 2000.

In 2003, the couple married, and Oleksandra was born a year later. Kyrylo, their son, was born in 2013.

Zelenska, like her husband, who holds a law degree, left academia to pursue a career in show business.

According to UNIAN, she assisted Zelensky in developing stand-up routines for the Russian TV comedy show KVN, and then worked as a scriptwriter at the TV production business Kvartal 95 Studio, which she co-founded.

Zelenska characterized herself as a "non-public person" who wants to be "backstage" in an extensive interview with Vogue Ukraine in 2019, just after her husband surged to power in a landslide election.

Her comedian husband's political ambitions were initially met with skepticism by his wife. She revealed in an interview with Vogue, which included a lavish picture shoot: "When I realized those were the intentions, I was not pleased. I realized how things would change, as well as the challenges we would confront."

"Let them pick how they want to live," she said, expressing her intention to safeguard her children while she adjusted to life in the public domain.

She has joined her husband on multiple official tours across the world in the three years after assuming the role of first lady, including to the United States, Japan, and France. Meanwhile, she has been able to devote her time and energy to a number of causes near to her heart, including "children's health, equal opportunity for all Ukrainians, and cultural diplomacy," she told Vogue.

She went on fact-finding missions to Latvia, Japan, and the United States, among other places, to improve school meals for children.

She is, of course, now focused on Ukraine's fight for survival. She started a Telegram group earlier this month to give tips on "how to act and live in times of conflict."

Zelenska, who was admitted to hospital with Covid-19 in 2020, updated her Instagram page hours after releasing her open letter with a photo of young cancer sufferers heading to Poland for safety and treatment.

She expressed herself as follows: "These are young Ukrainian cancer patients. They were only a few days ago hiding in the basements of clinics to avoid the shelling. They are now crossing the Polish border in search of safety and, more crucially, to continue their medical treatment. No attacker on the planet will be able to stop them from defeating the sickness!"

"Ukraine is halting the military that may aggressively enter your cities tomorrow under the pretence of defending civilians," she wrote in her open letter, reiterating her husband's demand for a no-fly zone.

"If we don't stop Putin from starting a nuclear war, there will be no safe haven for any of us in the globe."