In the world of children’s literature, siblings add a layer of depth and relatability. From Maurice Sendak's classic 'Where The Wild Things Are' to more contemporary wonders like 'Ramona Quimby, Age 8', sibling relationships abound in dynamic ways. While many books focus on the typical sibling rivalry and camaraderie, today, we focus on a specific typology - the narrative of welcoming a new sister and how it resonates with young readers.

The Impact of New Sister Books on Children's Psychology
Introducing a new sibling is a major milestone in a child's life, with multiple psychological implications. A situation ripe with feelings like jealousy, confusion, and even excitement is complex to maneuver. It is no surprise then, that such a shift in family dynamics extensively features in children's literature.

Books about new sisters can act as a blueprint, helping children navigate the real-world experience of gaining a sibling. These books encourage conversations between parents and children, making the complex situation more digestible. Furthermore, they also serve to validate feelings of resentment, fear, or loneliness that are otherwise difficult for children to express.

A Lens to Emotional Aspects
Literature delineating the arrival of a new sister comes packed with a wide range of emotional illustrations. These narratives invite children to delve into the emotional world of characters that, like them, are trying to understand the impact of this change. 'I'm a Big Sister' by Joanna Cole and 'Julius, the Baby of the World' by Kevin Henkes, portray an emotional journey that resonates with children while preparing them for similar experiences.

Empowering through Narratives
Books about new sisters often seamlessly show how to adjust and accept change, eventually turning the initial angst into endearing love and protective care. 'The New Small Person' by Lauren Child and 'Peter’s Chair' by Ezra Jack Keats beautifully reflect this transition. This narrative strategy empowers children to take charge and grow into their role as older siblings.

The Unifying Power of Shared Experience
A new sister book can serve as a confidence booster when a child connects with a character going through a similar experience. Such books can make them feel less alone and part of a larger shared human experience. Stories such as 'There's Going To Be A Baby' by John Burningham and 'Maple' by Lori Nichols do just that.

In conclusion, the exploration of 'new sister' narratives in children’s literature can serve as an invaluable tool for aiding children in understanding the confusing emotions attached to such changes in their lives. As we know, books have the unique ability to educate, entertain, and empathize, making their power in navigating such significant life events, truly transformative.