The parents of a US citizen who is at least age 21 are considered "immediate relatives," and therefore eligible for a green card, allowing them to live and work in the United States, Immigrating to the United States through a US citizen child is a possibility, but one that comes with major limitations

Yeah you can, as long as the child is fully compliant and has citizenship

i thinks you can

Yes, if your child is a U.S. citizen and over 21.