In general, yes, you can but with caution. Essential oil can be extremely beneficial for children however those little systems need much less than ours and in fact many times an essential oil hydrosol will do the trick for them.
ALWAYS check with your paediatrician before administering oils especially is this important if your child has allergies, asthma or chemical sensitivities.
Certain essential oils should not be used on children under 10 some on children under 5. Children have different requirements when it comes to amount of time with a diffuser, which oils they can apply to their skin, how often they can use EO’s etc….check with your specialist before using EO’s on children.
Here are a few oils to be cautious with on children however this is not a complete list – Peppermint, Eucalyptus, Clove, Oregano, Black Pepper, Melissa, Ylang Ylang