"Ursa is a horrible mom for choosing to forget her children!"
Except that this comic makes it clear that she didn't want to forget her children. She wanted to forget the pain of her life with Ozai. In Ursa's own words, "the pain of a life I did not choose myself."
Of course, her children are a part of that life, but Ursa being forced to make that choice, though it happens in a fantasy context, is all too common the story of women's lives. Ursa didn't get a choice about having children with Ozai in the first place, and Ozai specifically uses the children as a weapon against her because he knows she loves them.
Of course, Ozai doesn't and has no intention of keeping his part of the deal, but blaming Ursa for that is just a colossal failure of reading comprehension and a startling lack of understanding of how patriarchal institutions are set up to favor abusive men and keep women oppressed.
There's a lot in this comic I dislike, but the portrayal of the pain of a woman trapped in an impossible situation and forced into making a horrible choice is actually pretty spot on. The pain over having to choose to leave her children behind, children she never chose to have and cannot protect, and wouldn't have been able to protect from their father's abuse even if she had stayed, even if she hadn't chosen to forget. Every choice she makes compounds her pain, and every choice she makes impacts her children, but will not lesson the trauma they will be put through, either. In that kind of situation, there are no safe choices, for her or the children, and the system is set up that way on purpose. If you want to criticize someone, criticize the abuser, and the one who has the most power, and I assure you it isn't Ursa.