She can only withdraw her consent with the Court's permission. She would have to prove coercion or duress and that it would be in the best interest of the child for the Court to allow the consent to be withdrawn. The Court is to consider the totality of the circumstances including emotional stressors in determining whether or not the signing of any consent to adoption was involuntary or pursuant to duress or coercion.
See McCann v. Doe, Opinion #26468, filed April 7, 2008. The burden is on the person seeking to revoke the consent to show the consent was obtained involuntarily. Phillips v. Baker, 284 SC 134, 137, 325 SE2d 533, 535 (1985). See S. C. Code Ann. §63-9-350 (Cum. Supp. 1992).