With an attitude like that, it wouldn't surprise me that Harsen actually likes/loves Ercella, except he's got a twisted view of what he has to act and do because of his position as a Duke. Hence why he's so cold and distant, but the fact that he rushed into an early and young marriage with Ercella suggests an impulsivity that isn't really in character with his "role." :S Not sure if it's something he can be forgiven for, especially with how he's now blaming Ercella who is trying for the first time to be a mother.
On the topic of Ercella.... like let's be real she gave birth when she was a teenager, and lost her family members shortly before/after her pregnancy, and her husband was away at war. On top of that, any additional stress from people around her not being nice or amiable would really, understandably drive her to take it out on her child. It's not something to be proud of, but it's very understandable considering her circumstances. She wasn't ready to be a mother, pure and simple. The negative consequences of it we see now. It doesn't mean that it's not too late to try to be one now.
Also if they reconcile for whatever reason, she's still young enough to have more kids
she was what, 17? when she gave birth, now another 15 years later, she's in her early thirties...?