TAMPA — Rachel Canning checked the Instagram app on her iPhone before heading into her sorority chapter meeting Monday evening. Afterward, when she checked it again, she had 200 pending "follow" requests.

It's difficult to confuse Canning, a 22-year-old blond homecoming queen at the University of South Florida, with the 18-year-old brunet of the same name who is making international headlines this week. That Rachel Canning left her New Jersey home last year, sued her parents for child support and college money, and heard a judge on Tuesday deny her demands.

Yet commenters have bombarded the social media accounts of USF's Rachel Canning, especially her old Facebook campaign page for homecoming queen, mistaking her for the other Canning.

In a matter of hours, her page exploded with long lectures about how she should be more grateful. Commenters used profanity, told her how terrible she was, said they wished she would get hit by a bus. Some were as far away as Amsterdam. Middle aged men tried to strike up private-message conversations.

"At first, I thought, 'What the heck?' " Canning said. "I was more disturbed at the online bullying going on. Regardless, this girl's only 18. I couldn't believe there were full-grown adults that spent their day not only stalking this girl but sending bullying messages. . . . I've never been on the receiving end of anything like that."

Her personal Facebook page, which has strict privacy settings, drew little attention because it includes her middle name.

Canning, who was named USF homecoming queen in October, said her campaign Facebook page typically got three views a day before this week. Her last post — which explained that she clearly was not the infamous Rachel Canning of New Jersey — was seen by more than 10,000 users.

Many who left negative comments realized it too late and wrote follow-up posts apologizing to Canning. Some even posted links to the correct page, which Canning deleted.

One commenter posted an address to USF's student tuition payments account, urging others to donate to help Canning finish school.

University of Florida social media specialist Bruce Floyd explained that the misguided attention is part of the nature of social media.

Additional relative search terms like "New Jersey" might have ruled out Canning from Facebook search results. Like a Google search, people often click on the top results.

"Not everybody's a journalist," he said. "Some people just go with the first thing they find."

As for the comments, "there's something empowering about being able to get behind a keyboard and speak your mind," Floyd said. "It gives people the courage to say things they wouldn't normally say in a more physical setting."

At the suggestion of a friendly commenter, Canning decided to channel the Web traffic to a good cause. She posted a link to her fundraising page for the advocacy group, Autism Speaks. Canning will participate in a walk in April for her 19-year-old brother, Thomas, who has Asperger's syndrome.

As of late Wednesday, she had met 90 percent of her $150 goal.

"For Rachel to turn negative attention into something so positive shows what a great person and big sister she is," said Katy Formella, Tampa Bay manager for Autism Speaks.

In contrast to Rachel Canning of New Jersey, Rachel Canning the homecoming queen is financing her college education with a Florida Bright Futures scholarship, her salary from working in USF's Student Government and financial help from her parents.

Canning was raised in Connecticut but graduated from Clearwater High School in 2009. A senior at USF, she plans to graduate in May with a dual degree in international studies and communications, and a minor in leadership studies. She also served as president of her sorority, Delta Gamma. She plans to pursue a career in public relations.

Canning said she views the lawsuit in New Jersey as a family matter that went viral.

"It sounds like one of those high school struggles that the family should handle at a personal level," she said.

Canning's mother, Mary Canning, 57, said it was in her daughter's nature to do something so positive, especially to benefit her younger brother.

"I'm not commenting on somebody else's Rachel, but I think it's hilarious that people think it's my Rachel," she said. "She's like the nicest daughter on the planet. . . . I'm lucky she's my kid."

Colleen Wright can be reached at cwright@tampabay.com or (727) 893-8913. Follow her on Twitter @Colleen_Wright.