One benefit is comfort. Your own bed is a familiar place, with your favorite pillow and blanket. It gives a sense of security. Another is better sleep quality. You can adjust the environment in your room for optimal sleep, like adjusting the temperature or the lighting.
Once upon a time, there was a kind grandma. Every night, she would tell her grandchild a story about a magical forest. In this forest, all the animals could talk. There was a little rabbit who was lost. But with the help of a wise old owl, the rabbit found its way home. The grandma's soothing voice made the grandchild fall asleep quickly, dreaming of that magical forest.
Definitely not. Grandma - given sex stories are extremely inappropriate to share. This kind of content is not suitable for public discussion or even private chatter. It can make people feel uncomfortable and violate family values.
Just smile and share a little summary of the book with her. Maybe she'll join you in reading it later. For example, if it's a book about adventures, you can tell her some exciting parts.
Grab a broom or something long and poke under the bed. If there really was something strange, it might make a noise or move. But chances are, you'll just find some dust bunnies or lost items. Also, you can call for someone, like your parents or siblings, to come and check with you. Their presence can make you feel safer.
You should immediately address the situation in a positive way. Since she's your little sister, she may be just being innocent or not fully aware of social norms. Take her to a place where she can put on some clothes, like her room. After that, you can have a little chat with her about why we wear clothes. For example, clothes keep us warm and also are a part of our privacy. You can also use this as an opportunity to teach her about good behavior and respect for others' personal space.
First, you should immediately cover her with a blanket to preserve her modesty. Then, gently but firmly explain to her that this is not appropriate behavior. It could be that she doesn't fully understand the concept of privacy yet. You can also tell your parents or guardians about the incident so they can have a proper talk with her about appropriate behavior and privacy.
You can offer her a special treat if she sleeps in her own bed for a certain number of nights. For example, a small toy or a piece of her favorite candy.