Please consult personally with an attorney before you meet with DCF. You want someone who has dealt withaujtism and dcf as well.
This is not legal advice until I am retained and have reviewed all facts about your situation.
I agree that you should consult with an attorney and have one present when you meet with DCF, if possible. You should however, be sure to hire one who is familiar with Care and Protection Cases and regularly practices in the local Juvenile Court. They will have insight into both the practices of DCF in your area, and possibly the caseworker or supervisor. If it has taken 9 days to contact you, it could be that they have already contacted the school, therapist and pediatrician and are now ready to (hopefully) close the case, but cannot do so until they meet with you. They will most likely want to come to your home and will thoroughly check it out. Confirm there is food in cabinets, sleeping arrangements are appropriate, and that you are not inflicting harm when you punish your child. They will also be assessing your attitude with them, do you recognize that it is their job to protect children and that they need to investigate the issue raised about your child. Your goal is not be defensive (which admittedly may be difficult), but to show, not only tell, them, that you are a concerned parent who is not abusive to their child. Good luck.
This is not legal advice; much more information would be required to provide specific advice for your situation.