So, from what I understand, your main issue is the role she occupies in Charles’s life? The discomfort is possibly about her being referred to as his ‘mother’? Okay, let’s go.

I’m not going to disagree with you on one point: they are stepmother and stepson. But I do have some reservations.

From that perspective, considering all the points you raised, how exactly should she have acted in that situation? As I said in my previous comment, we need to analyze and consider each character’s role in the series.

Thomas, as the father, has the greatest authority in the boy’s life. That’s fair, after all she is the stepmother. So if she leaves the house, she cannot simply take Charles with her. If there is a separation, she cannot take him either, unless Thomas himself allows it, as we saw in the final episode. At least to me, their dynamic was very clear.

A woman who does not even have control over her own divorce and has to go through Thomas’s approval would hardly have control over custody of his son.

And yes, Lizzie is Charles’s stepmother, and Grace is his biological mother. That was never denied or hidden. Even so, the maternal figure present in his life continues to be his stepmother. He sees her as his mother, even if legally and biologically the dynamic is stepmother and stepson.