If you are an adult (over 18) and sell or supply prohibited drugs to a child (under 18), it is considered to be far more serious than sell or supplying to another adult.
Anyone who is convicted of possessing, selling or supplying more than 28 grams of methamphetamine can face a sentence of life imprisonment.
The penalties for drug charges vary depending on the quantity of the prohibited drug found, whether it was for personal use or sale or supply to others. There will be differences in penalties if you are under the age of 18 or an adult. You will need to get legal advice about your particular situation.