Doe v. Franklin, 930 S.W.2d 921, 922-23 (Tex. App.--El Paso 1996, no writ), concerned a grandmother sued for negligence after the grandfather molested a child The grandmother had undertaken the care and supervision of the child. Id. at 928-29. Once she did so, the grandmother assumed the duty to not leave the child alone with a person she knew or should have known had previously molested the child. Id. at 929. Thus, the duty arose from an affirmative act of the defendant, that is, leaving the child alone with the grandfather after having assumed caretaking responsibilities for the child. Id.