There is no need to add them as dependants if they do not live with you. As per the Canada Revenue Agency (CRA) If you do not have a court order or written agreement, the payments are not subject to the tax rules that apply to support payment. You cannot deduct any of the payments made and do not have to report the payments received on your tax return.
More information from the CRA: Amount you can claim or report
Please see our TurboTax FAQ for guidance: How do I enter child support payments made or received?
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