HOUSTON—Through her tears in jail, Shanell Mosley tried to explain to KHOU-TV why her kids were left alone while she traveled 11,000 miles away to Africa to get married.

In January, deputies found her 15-year-old daughter in charge of seven other kids.  The youngest was just a year old.

But just how old does a child have to be before they can legally be left on their own?

“It’s the question that we’ve asked most often,” Gwen Carter of CPS said.

The answer is, there is no specific age defined by law.

“There is no age. But what we tell people is that as a reasonable adult, you know, you have to know your child,” Carter said.

The standard in the state of Texas is called “neglectful supervision.”

That means officials have to determine if a child was left in a place or situation that a “reasonable person” would consider harmful or wrong.

Take the case of Sandra Medrano, for example.

Medrano left her 5-year-old son and 1-year-old daughter home alone with a burning candle last October.

The house caught fire, a neighbor rescued the kids and now Medrano is serving 100 days in the Harris County Jail for child abandonment.

A study by the Urban Institute in Washington DC found that as many as 12% of children between the ages of 6 and 12 are left home alone while their parents are at work.  That’s more than 3 million kids nationwide every day.

“So we ask parents to always, always practice good judgment,” Carter said.

That judgment is not based on a child’s age, but on whether a grand jury believes a parents actions were appropriate.

And now Mosley can only wait to see what a grand jury thinks of her.

CPS asks that parents begin making summer plans now for the children.  The problem of children being left home alone always gets worse after the last day of school.