AUSTIN, Texas - Laura McIntyre began educating her nine children more than a decade ago inside a vacant office at an El Paso motorcycle dealership she ran with her husband and other relatives.

Now the family is embroiled in a legal battle the Texas Supreme Court hears next week that could have broad implications on the nation's booming home-school ranks. The McIntyres are accused of failing to teach their children educational basics because they were waiting to be transported to heaven with the second coming of Jesus Christ.

At issue: Where do religious liberty and parental rights to educate one's own children stop and obligations to ensure home-schooled students ever actually learn something begin?

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"Parents should be allowed to decide how to educate their children, not whether to educate their children," said Rachel Coleman, executive director of the Massachusetts-based Coalition for Responsible Home Education.

Like other Texas home-school families, Laura and her husband Michael McIntyre weren't required to register with state or local educational officials. They also didn't have to teach state-approved curriculums or give standardized tests.

But problems began when the dealership's co-owner and Michael's twin brother, Tracy, reported never seeing the children reading, working on math, using computers or doing much of anything educational except singing and playing instruments. He said he heard one of them say learning was unnecessary since "they were going to be raptured."

Then, the family's eldest daughter, 17-year-old Tori, ran away from home saying she wanted to return to school. She was placed in ninth grade, since officials weren't sure she could handle higher-level work.

The El Paso school district eventually asked the McIntyres to provide proof that their children were being properly educated and even filed truancy charges that were later dropped. The family sued and had an appeals court rule against them, but now the case goes Monday to the all-Republican state Supreme Court.

In court filings, the McIntyres say the district is biased against Christians and accuse its officials of mounting a "startling assertion of sweeping governmental power."

Most of her children are now grown, but Laura McIntyre is still home-schooling her youngest.

"We are definitely looking for a little clarification," Laura McIntyre said briefly by phone. She, her husband and other relatives subsequently didn't return messages seeking further comment.

McIntyre said in court filings that she used a Christian curriculum to home school that was the same taught in the private El Paso religious schools her children attended before she began home schooling them in 2004. She and her husband also say that a separate legal dispute between them and Tracy McIntyre for control of the now-defunct motorcycle dealership made him a biased witness.

Between 2003 and 2012, the number of home-school students nationwide jumped by about a third to 1.7 million, now estimated at more than 3 percent of all students, according to the National Center for Educational Statistics.

The Texas Home School Coalition estimates 300,000 students are home schooled in the state - more than one-sixth of the national total.

No one knows for sure since Texas is one of 11 states that don't require home-school families to register. And 14 states have no subject requirements for what's taught, according to Coleman's Coalition for Responsible Home Education, which advocates for greater home-schooling accountability.

Texas mandates a written curriculum providing a bona fide education "designed to meet basic educational goals" in reading, spelling, grammar, mathematics and citizenship. But it doesn't require home-school students to take standardized tests or otherwise show progress, making the standard unenforceable.

In all, 24 states have rules that home-school children undergo some form of assessment, usually via standardized testing or portfolios of student work. But only nine mandate that home-school families turn in test scores or other assessments to state authorities to ensure student progress is made, the coalition says.

"Part of the problem is, on the political right they'll remove oversight to score points with their base and there isn't a strong enough opposition to that on the other side," said Coleman, who was home schooled in her native Indiana. "This happens especially in states where their legislatures are more conservative."

State lawmakers in Arkansas this year repealed a law mandating that home-school students take nationally recognized standardized tests, and Utah removed academic requirements from its home-school students in 2014. Pennsylvania, Iowa, New Hampshire and Minnesota have also recently moved to relax home-school standards.

Still, Stephen Howsley, a Texas Home School Association public policy analyst, calls his state the country's "most home-school friendly."

But, depending on the outcome, the McIntyre case could change that.

"No parents have ever prevailed in any reported case on a theory that they have an absolute constitutional right to educate their children in the home," 8th Court of Appeals Chief Justice Ann Crawford McClure wrote in ruling against the family last year.