For three years, she had worked as a music teacher for children suffering from autism, learning difficulties, and cerebral palsy -- many of whom live in orphanages.
Her employers were satisfied with her work. And by all accounts, she was well liked by her pupils.
But Anastasia, who used a pseudonym for this article, is a lesbian. And in today's Russia, where the propagation of "nontraditional sexual relations" to minors is illegal, that was enough to get her fired.
The so-called "gay propaganda" law, which came into effect last year, has unleashed a wave of homophobia in Russia, including violent assaults on homosexuals, firings, and other forms of discrimination.
In a report this month, Human Right Watch said the law effectively legalized discrimination against lesbian, gay, bisexual, and transgender (LGBT) people and cast them as second-class citizens.
According to an account on the Russian news site Meduza, Anastasia's troubles began on December 8, when Timur Isayev, a self-styled antigay activist, approached administrators at St. Petersburg's Primary School No. 565 and demanded she be fired.
Isayev, who boasts being behind the dismissals of 29 gay teachers from schools across Russia, produced photos from Anastasia's account on the social-networking site VKontakte showing the woman embracing her female partner.
Other "incriminating" evidence was the fact that on VKontakte she had "liked" Russian singer Zemfira, who is widely believed to be a lesbian, and Zemfira's rumored former partner, actress Renata Litvinova.
Meduza reported that Isayev gave school officials a letter describing Anastasia as an "immoral" lesbian with "psychiatric abnormalities" who cohabitates with an equally "unhealthy" woman.
Isayev's letter, which was also sent to St. Petersburg city authorities, reportedly said Anastasia's continued employment at School No. 565 would violate Russia's law prohibiting "gay propaganda."
According to the account in Meduza, the school's director, Stanislav Vinogradov, told Anastasia he had "no choice" but to fire her.
"As far as I know, the city vice mayor passed the information to the education committee, the committee sent it to the district head, the district head passed it to the deputy, and the deputy district head has approached me," Vinogradov was quoted as saying.
Local authorities in St. Petersburg's Kirov district, where the school is located, reject the accusation, saying decisions about teachers' hiring and dismissals rest with school administrations alone.
Anastasia, meanwhile, is determined to get her job back at the school.
Ksenia Kirichenko, a lawyer with Vykhod, an LGBT rights group in St. Petersburg, says Anastasia is taking her case to court. "We will file the lawsuit by the end of December, demanding the court rule that Anastasia was unlawfully dismissed and discriminated against," Kirichenko said.
Several gay teachers -- as well as heterosexual teachers who openly support LGBT rights -- have either been fired, pressured, or forced to resign since the "gay propaganda" law came into force.
In its report this month, Human Right Watch documented seven such cases across Russia.
Among them was Aleksandr Yermoshkin, who lost his job as geography teacher in Khabarovsk for being openly gay.
Yekaterina Bogach, a Spanish-language teacher from St. Petersburg, and Olga Bakhayeva, a teacher from Magnitogorsk, were targeted for their support for gay rights.
Bogach kept her job despite an online harassment campaign by an antigay group that claimed her involvement with the Alliance of Heterosexual People for LGBT Equality was harmful to her students.
Bakhayeva, however, was forced to resign after a group called Parents of Russia had complained to education authorities about her stance on gay rights issues.