If you find out that someone has stolen your child's identity, here are steps you can take to help minimize the damage.

Contact the three credit bureaus. If you discovered that a credit report fraudulently exists for your child, contact each of the three major credit bureaus and ask them to remove the fraudulent accounts, as your child is a minor. You can also place a credit freeze on their credit file until your child is old enough to apply for their own credit, says the FTC.
Report the identity theft to the FTC. The reporting process will typically include answering some questions about the situation and creating a personal recovery plan.
File a police report. You may need to contact your local police department to file an identity theft report, according to USA.gov.

By taking a few proactive steps and staying alert to early warning signs, you may be able to help keep your child from becoming a victim of identity theft. And remember, if your child's identity does get stolen, it's important to act quickly to help minimize the damage.