I would suggest that you have a solicitor represents you on the mention and it may necessarily be required that you get a further adjournment so that he can prepare a case for you.
I suspect from what you've told me that the incident that resulted in your child being afraid to stay at home was because of the incorrect medication by you, and if it can be explained why it happened and that it will not happen again you may be able to get the case dismissed and the child returned to you.
But you will need to have a solicitor represent you on the day.
Do not attempt to do this on your own because the courts are inclined to listen to child services as it is their job to protect the children.
You should contact the Law Society of Queensland and get a referral to a solicitor practices in the area of child protection.
Their website is as follows:
Provided it can be shown that this was the sole reason for the child's fear and that it will not happen again and you will put things in place to make sure it does not happen again I believe the court may make orders the child be returned home.
But please do not appear on your own on the day. If you cannot get the solicitor for the Wednesday get a letter from them to get an adjournment for the mention to be moved over to a day that they can appear.
I hope this is of assistance. If I have missed anything, or you have any further questions please let me know before leaving any feedback.
If I have assisted please do not forget to leave me with positive feedback.