In the fact pattern: "After her baby was born, Sally told one of the doctors at the hospital that she intended to place the child up for adoption. She signed an affidavit in which she provided an incorrect surname for the biological father and claimed she didn't no the biological father's address. As a consequence, the biological father was not informed of the birth and was initially unaware he had a daughter."

Why did the mom sign an affidavit? What was the affidavit for - Explain.