The Therapeutic Power of Sibling Authorship

I'm getting the sense that there's something quite emotional about these creations of only children from this vantage point of sibling authorship. Is it purely an emotional exercise or is there also maybe a literary reason to adopt a different vantage point when you're looking at a family? With therapeutic in the sense that these characters are usually fighting for their lives, fighting for their existence and freedom of self invention. It marks you off in a particular way and not only as a success, and that's one of the difficulties that comes with this territory. When a writer is born into a family, the family is finished, in some sense. What's it like for the others? I mean, it's hard