Why would very young daughter kill her own mother? Anya died when Ian was a child and Ares was a baby. And Ares doesn't even have any resemblance of Anya in her appearance. Ian has the same eyes as Anya but Ares has nothing to relate to Anya, it means, Anya isn't Ares' mother. Ares can be 100% the child of the family or she's adopted, maybe, it's actually her secret. Or maybe, her secret is that she's not sick, she's just sociophobic, and Ian knows it, so he lies to Ares' school his sister is sick.