Thank you for your query on Healthcare Magic.
Co-codamol contains codeine
As you have seen and it was a small amount that the child is ingested nothing to worry.
But look for the following danger signs :
Distention of abdomen and constipation
If you find any abnormal symptoms or signs immediately report to emergency.
Usually it takes 12 to 24 hours for the complete clearance of the drug from the system.
Hope I have answered your query.