Parents can add family rewards or online rewards for any kid in the family. When you enter a reward, you can specify how many points the reward is worth and which children the reward is made available to.
When your kids have earned enough points for a reward, they can request to redeem it. The cost of that reward will be deducted from their available points balance once they request to redeem. Once you approve the reward, it's theirs (but it's up to you to follow through!). If you deny the request, they'll get their points back.