I have 3 children who received orphan benefits (child benefit) for 2016, as their father passed away. Do I need to report that as net income for each of them?

How old are these children? Is this benefit reported on a T4a(p)?

The children are 14,12 and 9. Yes the benefit is reported on a T4a(p).

Report the income under the "Deductions" tab > "Additional Dependent Information"

I have same question except I only have one child so I am claiming equivalent to spouse.  But do I put my sons T4A slip as income he made?

As the CPP benefit would be reported as income to the recipient (even if they do not file a tax return) you must indicate that they have a Net Income for the purposes of calculating additional dependant amounts on your tax return.  If the amount is paid to you on the child's behalf and is included on your T4A(P) then report this income on your tax return and indicate the child does not have income.