Looking for my sister adopted to family in Winona, MN

I have a half sister that my mother gave birth to in November of approx 1968. From what I understand she was adopted to a family in Winona, MN. She would be approximately 36 years old. My mom named her Lisa, but never saw her again after the initial birth. My mom, sister, and brother would love nothing more than to get in touch with her if she wants to be contacted. We do not wish to disrupt her life if that would be the case. Does this sound like a familiar person to anyone and if not, does anyone know the quickest way to find her?