I have no shred of pity for that abusive woman, she can go fly a kite together with her son. A stepmother abusing a child is something one wouldn't count out because the child isn't their blood even if it is still not justified, but woman you gave birth to her just to treat her like that, nah you can rot. They just blamed Tia existence for why they couldn't easily get the throne. Also, she is the one who chose to put her love and energy into her son who would readily throw her away if it suited his purpose, that shit is on her.
Also the foreshadowing about how men's feeling are fleeting, while she was beating on Tia seems to be coming full circle, because Tia plans to throw a wretch in her relationship with the Emperor. Once she loses the Emperor's favor, as well as her greedy son's love I wonder what her fate would be. In the first time line they never mentioned what happened to her. And if she was alive, and she allowed Lawrence to do that to his sister, she is a new level of shitty.