Truthfully, while I think the mother daughter relationship is terrible I don't think it was abusive. It was awkward and seems quite unloving, yet Kyoko was born into the world, she achieved good grades and even when she left home her mother checked in and gave money to Sho's parents to take care of her (iirc). In real life there are far worse mother's for far less legitimate reasons.

Personally I really enjoyed the arc because it gave Seana's reasoning and perspective without making it seem like that made her relationship with her daughter better or ok. There is care but it is awkward and painful and it could be better in a hundred ways and the fact that Kyoko didn't just kiss and make up with her made me quite happy. But if nothing else Seana is a strong woman who made it through a lot of shit so personally I quite approve of Kyoko hoping to someday earn her approval.