Yes, if you hold a valid power of attorney to act on their
behalf. Otherwise no.
Signing for someone you do not hold power of attorney for is
fraud, and against the law.
View page
In general, parental rights are terminated either preparatory to
an adoption, or after a trial in which it is determined that the
parent is unfit. In any case, termination of parental rights does
not, in itself, terminate child support.
View page
The Signing of the Declaration of Independence was a very
important date in US history. It was not signed on the 4th of July,
but on the 1st of July in 1776. Eight of the 56 signers were
British.