Yes, there are many. For example, stories about a babysitter sister who helps the kids with their homework, plays educational games with them, and takes them on adventures in the park. These stories focus on the positive and nurturing aspects of babysitting.
No, it is completely inappropriate. Such content is private and often not suitable for family members to be involved with. It violates the boundaries of a healthy family relationship.
No, it is not appropriate at all. Incestuous themes are considered unethical and not acceptable in most societies. Such content is also against moral and family values.
An 18 - year - old sister might contribute financially. If she has a part - time job, she could use some of her earnings to pay for her own expenses like clothes and entertainment, which helps the family budget. She could also save up and contribute to family vacations or big purchases. Additionally, she can be a great emotional support for her family members. If her younger siblings are having problems at school, she can offer advice and a listening ear, just like a good friend would.
The sister could choose to simply ignore it as it is his personal matter. However, if she is concerned about his well - being or the family environment, she might consider talking to a trusted family member or a counselor in a general way about the importance of appropriate family boundaries without specifically mentioning the erotic stories. This way, she can promote a healthy family environment without directly interfering in her brother's private affairs.
Literature typically focuses on positive values and relationships. Stories with such inappropriate content are not the mainstream and are not worthy of promotion. So no.
One story could be about taking your baby sister to a park when she's scared. You hold her hand and show her the beautiful flowers and friendly squirrels. The colors and the gentle animals make her forget her fear.