This is a victim's rights issue. There are two ways to do this. One way is to seek restitution through the criminal action, which is usually ordered during the sentencing phase. In most states, you can recoup money from parents up to a certain amount - in Arizona it is $10,000. The second way is to sue them civilly. Be sure to include the parents as civil law also provides for including the parents under certain circumstances. A lawyer can be helpful for either or both of those issues.
This answer does not establish a lawyer-client relationship and is meant as general information only. A reliable, specific answer depends on a full meeting and your specific case facts.
The Texas Crime Victims Compensation Fund might be able to assist you. It helps victims of violent crime, and aggravated robbery with a deadly weapon should qualify. Contact the DA'S office and the juvenile probation department. Both should have victims' advocates who can help you with the paperwork. Good luck. Oh, and they should pay for counseling too if you're needing it to cope.
Normally part of a sentence is the restitution component. You can check with both the prosecutor's office and/or the probation department to see if such an order was made.