Whitefield Academy in Louisville, Kentucky expelled the girl in an email over a picture “which demonstrates a posture of morality and cultural acceptance” counter to their beliefs, her mother told local media.
Kimberly Alford said the message included a Facebook post of her 15-year-old daughter’s birthday celebrations, which shows Kayla smiling next to a multi-coloured cake.
Rainbows are associated with LGBT+ pride, but Ms Alford claimed the cake did not hold any symbolic meaning for her daughter, a now-former student at the private school.
“I ordered the cake, she didn’t,” she told The Washington Post.
“Rainbows don’t mean you’re a certain gender or certain sex or sexuality.”
The picture followed a series of “lifestyle violations”, the Christian school reportedly said in their email.
Bruce Jacobson, the headteacher, called media reports the pupil was expelled over just a social media post “inaccurate”.
“In fact, she has unfortunately violated our student code of conduct numerous times over the past two years,” he told local newspaper the Courier-Journal.
Kayla had previously gotten into trouble for taking e-cigarettes to school, according to her mother.
“Our code of conduct is on par with other private Christian schools in our area,” the school said.
Its handbook says the school has the right to “discontinue enrolment” if a pupil’s home environment is different from the “Biblical lifestyle the school teaches”, including on the subject of “homosexual orientation”.
It says such differences mean “it will be difficult for the school to cooperate with the home and achieve the goal of a student becoming Christ-like”.
Atheist parents launched a legal challenge against a school in the UK this summer, claiming children were being “indoctrinated” by Christian assemblies.
They dropped the case after Burford Primary School in Oxfordshire said they would put on other activities during collective worship.
Written by: Zoe Tidman