as I read chap 22 of the flower dances and the wind sings, I could say postpartum depression really sucked. Arcella just gave birth to her son and she felt depressed but Garden has duties as a duke so he couldn't be there for her then Arcella felt insecure and doubts her child if he's really her son. then it comes to a point where she didn't do her job as a mother anymore, thus, her son grew cold.
edit: i gave this 5 stars now because i think she is somehow becoming a better person and i just want her to be happy
edit2: dude just read recent chapter what drugs are you on arcella
The Flower Dances and the Wind Sings