My cousin is eating chalk from past three years is it bad?

theres a show on people who eat inedible things, you should sign her up haha. i dont think eating things thats not meant to be eaten is good, but the girl on that show that also ate chalk, has been eating it for 11 years, and she had no serious health problems. the only thing they said, is that since its not a food product, the manufacturers arent as careful to make sure the chalk is sterile. so the only thing that could really happen, is that she got sick from whatever bacteria were on the chalk.