Question: What is the legal relationship between the daughter brought by my stepfather and me?

It is a sister relationship and a legal relationship. What is clearly stipulated in the marriage law and inheritance law is that the relationship between step-sisters is nothing more than a step-sister relationship. You are both the first in line of succession, and you both have the obligation to support your step-parents, and the step-parents also have the obligation to support their step-children.

Emotionally, I can completely regard her as a bloodless relative. Best wishes