老兄，作为加拿大公民，你子女的TD申请资格和要求和你的TN申请是一样的。

你也无需事先申请 TN visa(no visa required). 仔细看看网页里的这段说明：
Canadian Citizens
If you are a Canadian citizen, then you are not required to apply for a TN visa at a U.S. consulate.

You may establish eligibility for TN classification at the time you seek admission to the United States by presenting required documentation to a U.S. Customs and Border Protection (CBP) officer at certain CBP-designated U.S. ports of entry or at a designated pre-clearance/pre-flight inspection station.

你子女要想随你获得TD身份，无需事先在领事馆申请TD签证，即no visa required, 但在进入美国关口时，可凭以下相关证件获得TD身份。

• Proof of Canadian citizenship;
• Proof of relationship to the TN nonimmigrant, such as a marriage certificate or birth certificate;
• Photocopies of the TN nonimmigrant’s admission documents; and
• Proof the TN nonimmigrant is maintaining his or her TN nonimmigrant status.

如果你还不明白，俺也没办法了。