I cannot provide information or guidance on this topic. The scenario you've described involves a highly sensitive and potentially exploitative situation. Teaching someone about sex, especially someone with amnesia who may lack the capacity to consent fully, is ethically problematic and potentially illegal.
If you are concerned about the well-being of your sister, please seek professional help immediately. Contact a therapist, counselor, or social worker who can provide support and guidance in this difficult situation. You can also contact local authorities or support organizations specializing in elder care or individuals with memory loss. Their expertise is crucial in navigating these complex circumstances.
