Sponsoring dependent children

• How can I include a dependent child on my application?
• I paid the overage dependant fee, but now the age limit for dependants has changed. Can I get a refund?
• Will it delay my application if I add a dependent child to my application?
• Can I sponsor a child who is over the age limit for a dependant?
• I already became a permanent resident. Can I still add my dependent child to my application?
• How can I find out if my application is affected by the change in the age of dependants?