“Something good has to come of this,” Deanna Gresko tells PEOPLE after daughter Nadiya Santiago’s death

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A mom says her 11-year-old daughter, who had been bullied for months, died by suicide after sharing a dancing video she never meant to post on social media.

Deanna Gresko tells PEOPLE that despite doing “everything together” with daughter Nadiya Santiago — a “sweet” middle school student who sang in church, loved soccer and was known to her loved ones as “Nana” — she had no idea anything was wrong until the night before her daughter’s death.

“I don’t know why she didn’t tell me. She knew I would’ve tried everything,” Gresko says. “I would’ve even pulled her out of the school if I knew.”

Around 9 p.m. local time on May 18, the 47-year-old certified nursing aide in Lackawanna says her son showed her a video on his sister’s phone.

Nadiya, who had fallen asleep earlier that evening, woke up hours later and realized she had accidentally posted the video.

Her brother also said that “some kids” were talking about Nadiya online.

“It was just a little cute video or her doing one of those little TikTok dances in her room. And she looked so cute,” the mom of 10 recalls. “I was like, ‘What possibly could they have said?’ ”

Her mom, who didn’t get a chance to read the comments herself, says her daughter didn’t say much about it at the time.

“I said, ‘Well, what are they saying?’ And she was like, ‘Nothing bad, but I’m embarrassed. Can I stay home tomorrow?’ ” Gresko recalls.

Even when she tried to get more information, Gresko says her daughter replied, “ ‘I don’t know, mom.’ ”

“I’m like, ‘Well, delete it. Don’t listen to them,’ ” Gresko adds.

In response, she says her daughter just said, “ ‘I know, mom. I know.’ ”

The next day, her mom remembers walking into her daughter’s room and seeing Nadiya sitting there on her phone. When she asked if anybody was still saying anything, her daughter said the video had been deleted.

Gresko says she tried to encourage her daughter not to let what happened get her down.

“I was like, ‘You know people like that, they’re not good people,’ ” Gresko remembers telling her daughter. “And I was like, ‘I’ll go to the school if they’re from your school because I’m not going to let nobody hurt you like that or anything.’ And she’s like, ‘Okay, mom.’ ”

When it came time to pick up the rest of her kids after school, Gresko says she asked if Nadiya wanted to come with her, but her daughter wanted to stay behind.

A short time after she returned home roughly 40 minutes later, Nadiya’s body was discovered.

After her daughter’s death, Gresko says one of Nadiya’s friends told her a group of kids from school had been “picking on her really bad” for months — and that the friends, as well as Nadiya, “told the teachers and the principal.”

But Gresko, who alleges that some of her older children had also experienced bullying at the school, says the school never contacted her.

“They didn’t even call me to say, ‘Hey, your daughter’s having a problem. You might want to talk to her,’ ” she shares.

In a statement obtained by CBS affiliate WIVB, the district said it was “equally concerned” and took “this matter very seriously.”

Officials added that a “Dignity for All Students Act” investigation is ongoing, “which requires school districts across New York State (NYS) to strictly report incidents of bullying and harassment.”

The Frontier Central School District did not respond to PEOPLE’s requests for comment.

Gresko says she also later learned from one of her daughter’s siblings that Nadiya had mentioned at one point that some kids were picking on her.

“I was like, ‘Why didn’t you tell me?’ And she’s like, ‘Well, mom, Nadiya told me not to. She’s my little sister and she didn’t make it sound like it was really bad like that or I would’ve told you,’ ” Gresko says.

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In the months since her daughter’s death, Gresko says she’s been left “brokenhearted” by the response from officials.

“The police aren’t doing anything. The school’s not doing anything,” Gresko claims. “The school, they didn’t even put her picture and her name in the yearbook. They’re trying to erase her.”

Gresko shares that she wants Nadiya’s death not to be in vain and to help other children who are being bullied.

“She loved everybody, cared about everybody,” Gresko adds. “She didn’t have a mean bone in her body. And I want her to be remembered as the light that she was.”

Meanwhile, a GoFundMe fundraiser has been launched not only to hopefully “raise awareness” and support other “families facing similar struggles,” but also to help with funeral arrangements and other personal expenses following Nadiya’s death.

“There’s people out there that will help you and listen to you and don’t make people make you feel any less than what you really are to where your loved ones are suffering after something like that,” Gresko says.

“Your family’s the one that lives in hell for the rest of their lives,” she continues. “And if it can save one kid, something good has to come of this.”