BibTeX:
@incollection{Various,
  author = {Various},
  title = {Brothers and Sisters for Twinkle},
  booktitle = {Baha'i Stories for Children},
  url = {https://bahaistoriesforchildren.blogspot.com/2016/02/brothers-and-sisters-for-twinkle.html},
}

APA:
Various. Brothers and Sisters for Twinkle. In *Baha'i Stories for Children*.

MLA:
Various. "Brothers and Sisters for Twinkle." *Baha'i Stories for Children*, n.d..

Chicago:
Various. "Brothers and Sisters for Twinkle." In *Baha'i Stories for Children*, n.d..