wdym? it's kinda obvious that she was brought back to the past to give her a chance to address her postpartum depression and its effects in her life. give her a break. it's not easy to become a mother at such a young age in a horrible environment with no one supporting you. hell, her own husband is emotionally stunted, so why are we expecting so much from her?
...Bruh have you ever been clinically depressed before? You literally cannot will yourself out of depression. She didn't have time to face Vincente, she couldn't even help herself. No one helped her either.
She had such a complicated life and complicated death, that her final wish and realization was to finally express the deep and conflicting feelings she felt for her son. --- which she can now pursue, now that she's more sound of mind.
Ercella married young, gave birth young, and then died really young---and was raised all her life to live and act a certain way because she comes from an imperial lineage, and because she's a woman. She was overly talented for a woman of her time, but she knew that society might condemn her for pursuing things beyond her station. She's only told NOW, by some passerby in this life time that it's OK for her to pursue these things. --- Our Heroine /is/ putting in the effort.

Call me emotionless but I don't the warmth yall talking about and thou it's a good manga I still don't get why she reincarnated, so she basically brush aside her child and when she finally on death bed she now want to see her child face.... Please she had precious time to play with her kid before being reincarnated. Ohh well human beings like being sympathic to those who has a change of heart but will forget what that person did in the past.