The relationship between Antigone and Ismene is that they are sisters. Antigone is a very strong woman. She has her convictions and acts upon them. Ismene, on the other hand, is more complacent than her sister. She does not distinguish right from wrong. Antigone is more strong-willed, while Ismene is compliant.
Antigone and Ismene show us much about their characters through the contrast and conflict presented in the first scene. Each sister depicts as a different perspective on the subject at hand: the burial of their brother, which has been outlawed under the penalty of death. Although each conclusion can be rendered reasonable, this situation also reveals their flaws, and even more, the reasons for the development of these flaws.
Once you share to someone that means you also care for them
The family feud between their two families separates them apart. As the prologue/beginning states, they were "star-crossed" lovers, kept apart by the hatred between their families, the Montagues and Capulets