Does a photograph show the wife of the vice president of Ukraine in military fatigues with a weapon fighting for her motherland? No, that's not true: Ukraine does not have a vice presidential position in its government, and the image is available from a photo agency where it is listed only as a "Ukrainian female soldier" in a 2021 military parade.
The claim appeared in a Facebook post (archived here) on February 27, 2022. It opens:
This is the wife of the Vice President of Ukraine. She is fighting for her Motherland. Massive Respect.
This is what the post looked like on Facebook at the time of writing:
(Source: Facebook, Tue Mar 1 19:57:21 2022 UTC)
Ukraine does not have vice presidents. The link to President Volodymyr Zelensky's page on the government website did not work at the time of publication on March 1, 2022, but is archived here. The Ukrainian government (this website was also down at the time of writing, but is archived here) consists of a president, prime minister, several deputy prime ministers and multiple ministers.
Using a reverse image search Lead Stories located the photograph of the smiling woman with red lipstick in military fatigues holding a weapon on the website of the photo agency Alamy. The caption of the photo reads:
Kyiv, Ukraine - August 22, 2021: Rehearsal of the military parade on occasion of 30 years Independence Day of Ukraine. Ukrainian female soldier
(Source: Alamy screenshot taken on Tue Mar 1 20:08:14 2022 UTC)
The military parade was held on August 24, 2021, to celebrate Ukraine's 30 years of independence, as Reuters reported here.