Can my cousin help me immigrate if she is American?

Theoretically, yes, but it is indirect, not direct

Your cousin is a citizen and can apply for her parents to immigrate

His parents If your immigration is successful and you are admitted as a citizen, you can apply for your parents to immigrate

After your parents' immigration status expires, if your immigration is successful, you can apply for your immigration status

You can then apply for immigration if your parents' immigration status expires. , you can immigrate to the United States

This is forty years later, and it must be said that the immigration policy of the United States has not changed at all in forty years. . . .