Definition of relative

as far i know step daughter is not included in the definition of relative u/s 2(77)

Step-daughter is not included in the definition of relative

Step Daughter is not included however indirectly it includes step father.

How she can become daughter without father, So even though it's not included in relative definition but from other family relatives point of view she also included in the definition of relative.

X is a father of Y (Step Daughter). From X point of view Y is not relative because she is her step daughter, but from Y (Step Daughter) point of view X is a step father which is considered under relative.

good clarification and information