I get your point, I also believe people can change but if I remember correctly, she's in this position because the new family she formed found out about hyesung and they didn't wanted her anymore, not because she decided to be alone. she had YEARS to reach to her son, she even had the opportunity to start over with him but she didn't. she decided to have a new ass family instead of trying to include hyesung in her life. she also knew the type of man his dad was and still left him with him, I get this bc she probably didn't have the money to provide both of them, but what about trying to save money, go for hyesung when she saved enough and then date someone if she wanted?
she's only changing because she had no other option:/ not because she wanted to do it

my baby hyesung is gonna feel betrayed once he gets to know dojin was the one who supported that woman evenn when he told him he didn't wanted her in his life:((( and I don't blame byul at all, bc he doesn't know the story behind everything but hyesung is gonna be upset with him too (but not as bad as with dojin, im sure). but I prayyyy fargo doesn't try to make hyesung feel pity for that woman, I don't want to see him forgive her, she abandoned him and even if she regrets it, he had a difficult life thanks to his parents, they don't deserve to be forgiven at all