What was Sara’s hebrew name? I was told that it was Iska.
You are correct that Sara is referred to also as Iska. But this does not mean Sara was not her hebrew name, rather Sara had other names which represented other sides of her. We know this because it is written in the Torah 'Avi Milka and Avi Iska' and our Rabbis learn that Iska was Sara. Similarly, the Midrashim teach us that Yitro and Moshe Rabbeinu both had 7 names - each name revealing a different aspect of their personality. Rabbi Baruch Kitay