- You cannot make a h&c claim if you don't have minor child.
- You can generally apply for H&C after 1 year.
- You must have a lawyer represent you and you should find a good one.
Please read this:
https://www.canada.ca/en/immigration-refugees-citizenship/services/refugees/claim-protection-inside-canada/after-apply-next-steps/refusal-options.html
The OP's case is a classic anchor baby case. They had 3 kids in US while they were unsure about their fate which probably ended up in family being separated. The other day someone said this in forum about giving birth in Canada as a refugee to "strengthen ties", which is absolutely garbage advice as the emotional toll this can have is tremendous. These routes can buy you tine, but at the end, if you don't have a valid claim, you will be sent home sooner or later.