Stephanie saw that Talia's mood was not good and she understood that after the incident with Cassie, Talia has every right to be upset.
Maya told Stephanie about Cassie accusing Talia of stealing food previously, so she knew that this was not the first time for Cassie to bully Talia. Stephanie also knew about the point that Damon was just standing there and didn't do anything while Cassie was doing her Luna-act, and Stephanie couldn't imagine how painful that would be for Talia. Damon is the one who brought her here with a promise for a better life, yet when it counted he stood on the side.
Stephanie's heart ached and she wanted to comfort Talia who was holding the ice pack on her face. "Let me see your cheek, dear…"