I will admit that I commented previously that the first time I saw the first update where we saw Edwin watching his mum do porn, that I did ask if incest would be a thing, maybe as part of showing Edwin's descent into debauchery, the final straw.
But the more the story has progressed after subsequent updates, the more I have come to understand that what his mum did is mirror to what all the Carnations are doing, especially for Rosalind.
The more Rosalind has spoken of her daughter to Edwin, and him seeing the impact of debt collector on Rosalind, the more Edwin understands that she will do whatever it takes to give the best life possible for her daughter, in the same way as his mother did for him.