You can only sponsor
dependent children.
Here is the definition from CIC:
Dependent child:
Your child or the child of your spouse or common-law partner can be considered a dependent child if that child meets the requirements below on the day we receive your complete application:
- They’re under 22 years old, and
- They don’t have a spouse or common-law partner
Children 22 years old or older qualify as dependants if they meet both of these requirements:
- They have depended on their parents for financial support since before the age of 22, and
- They are unable to financially support themselves because of a mental or physical condition
Dependants must continue to meet these requirements until they enter Canada.