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.
One common theme could be a guy trying really hard to impress a girl in non - sexual ways. For example, he might learn her favorite hobby like painting just to have something to talk about with her. Another theme could be the guy being there for the girl during tough times, like when she's dealing with family issues or stress at school or work. He sucks up to her by being a great listener and offering practical advice. Also, it could be about the guy doing small but meaningful things for the girl, such as bringing her favorite coffee every morning just to make her day better.
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.
The title 'Sister Sucks Brother Tim Story' clearly indicates that the two main characters are the sister and Tim, who is her brother. But we don't know if there are other supporting characters in the story without further information.
I'm not sure which specific 'Sister Sucks Brother Tim Story' you are referring to. There could be many fictional or personal stories with such a title. Without more context, it's difficult to tell the exact plot.