No need to panic you did the right thing by not including your Canadian citizen child on IMM0008. Here's s a breakdown to clarify things:
1. IMM0008 (Generic Application Form for Canada Who to include: Only non-Canadian family members who are applying for permanent residence (spouse, common-law partner, and dependent children).
Exclusion: Canadian citizens and permanent residents are not listed here because they do not need to be sponsored or included as dependents.
You were correct to only include your spouse and non-citizen child on IMM0008. Your Canadian citizen child does not go on this form as a non-accompanying dependent.
2. IMM5406 (Additional Family Information Form)
Who to include: All immediate family members (spouse, children, parents, siblings) regardless of their citizenship or immigration status.
You did the right thing by including both children on this form, even though one is a Canadian citizen.
Why was someone else's application rejected?
Their rejection was likely due to not listing all family members on IMM5406, which is required. Since you included both children on IMM5406, this does not apply to you.
Should you send a Webform to explain?
In your case, you do not need to send a Webform because you followed IRCC guidelines correctly:
You left your Canadian citizen child off IMM0008 (correct).
You included all family members (including your Canadian child) on IMM5406 (correct).
IRCC understands that Canadian citizens are excluded from IMM0008 and won't penalize you for following the rules.
