Erica Edgerly, 21, from Texas, US, shared the photo on Facebook on 2 April 2015, along with a caption explaining why she was angry about the situation:
"Today, my sister was sent home from school for wearing the clothes in the picture below," she wrote.
"And I'm sorry but I have to stand up for my family and for women who are degraded and judged for their bodies and clothing everyday."
"People wonder why women feel insecure about their bodies or what they wear... And it's because you're told your clothing is inappropriate when you're completely fully clothed, even when you're not showing cleavage or anything," Edgerly added.
"How about instead of body shaming women, school systems should start teaching 15-18-year-old boys to stop degrading women with their eyes and contributing to the rape culture of today's society.
"Bottom line, girls cannot go to school in comfortable clothes THAT COVER EVERYTHING because school systems are afraid that hormonal boys won't be able to control their eyes and minds.
"And that is such a bigger problem than worrying about clothing.
"No, I do not believe that all boys in middle school/high school degrade young women or sexualize their bodies.
"That is my point... this is not an inappropriate outfit, yet some are worried it might be seen that way, so they send girls home to change to try to avoid an issue and THAT is the problem.
"Not to mention, when you send someone home because of inappropriate clothing, you're taking away from their eduction.
"So I guess it's more important for boys to not have distractions (even when they're aren't any [Sic]) than a woman's education. When will people realize how big of an issue this really is?"
The post quickly went viral attracting more than 91,000 shares, with people commenting that they "couldn't see anything wrong with the outfit".
"I have been saying the same thing that you said for so long," wrote one commenter.
"Why should girls have to base their clothing choices on boys who can't learn to control themselves? Plus her whole body is completely covered so I don't see what the problem is."
In a later Facebook post Edgerly clarified that the school had taken issue with her sister's top because the sides of her shirt were not "fingertip length".
She also added that her original post hadn't been intended to directly criticise her sister's school, rather she had hoped to raise a point about a wider issue.
"My point is in no relation to the school board, the school district, or the administration specifically, (because again I know they were just doing their job) but society in general considering this happens all over the nation every day," she wrote on Facebook.
"So many young girls (and their mothers) have messaged me thanking me because their school sent them home for being fully clothed, but one part of their outfit hugged one part of their God given bodies a little too tight, and was seen as inappropriate and that is the real issue here."
“While the District cannot disclose or discuss the details of any student's disciplinary or educational matter due to federal and state confidentiality laws, we want to assure our community that Orangefield ISD strives to maintain a positive and successful learning environment for our students free from disruption and distraction, which includes enforcement of our student dress code,” superintendent Stephen Patterson said.
Dr Rory Fox, headteacher at Ryde Academy on the Isle of Wight responded with a letter on the schools website which read:
"We are preparing students for the world of work so it is important that we teach students about the importance of managing their appearance and working to a dress code.
"We have a number of female students who have recently said that they are coming under peer pressure to wear their skirts shorter than they feel comfortable.
"It is not fair that girls should be made to feel uncomfortable when they are just following the uniform policy. We have therefore decided to act at this point in time, to correct uniform issues."