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.
A good way to comfort a scared baby sister is by sharing a story of when you were scared too. I told my sister about the time I was afraid of heights. But then I overcame it by climbing a small hill step by step. I encouraged her to face her fear in the same way, and it really helped.
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 not appropriate at all. Incestuous themes are considered unethical and not acceptable in most societies. Such content is also against moral and family values.
There is the story of 'Goodnight Moon'. It has a simple and peaceful plot that can help her relax. Also, 'Where the Wild Things Are' can be interesting. Although there are some wild things in it, in the end, the boy returns to a warm home, which can make her feel safe.
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.
The story of 'The Velveteen Rabbit' is also very comforting. It tells the tale of a stuffed rabbit that longs to become real. Through love and the passage of time, it eventually achieves a kind of realness. It has themes of love, friendship, and growing up in a gentle way that's perfect for bedtime.
There's a story about a girl who moved to a new city and was really homesick. Her neighbor noticed and invited her over for dinner. They became good friends and that simple act of kindness made the girl feel less lonely and more comforted.