For children with serious conditions like cancer, medical marijuana is an option in Illinois. Parents or legal guardians who are over the age of 21 can apply for a medical marijuana card on their child’s behalf. In order for children to get a medical marijuana card, they must have a certification from two physicians. You’ll receive a caregiver’s card while your child will also receive their own medical marijuana card. You can use your caregiver’s card to shop at your designated medical dispensary for your child.