Actually, I think you can tell exactly the differences in which Odalia and Alador see their children with one simple item: Amity’s necklace.
The reason behind Amity’s “cute little accessory” was as shocking as it is maddening, especially when you consider that she’s had it since she was at least six years old. What the hell. In other words, Odalia has always been with Amity. So long as she’s worn her necklace, she’s never been free. Her mother can always pop into her head, always give her orders, always keep her in check.
Amity is someone to be controlled, to be pressured and packed and to be perfect. That’s the whole reason she exists. I mean, c’mon. It’s not like she was born because her parents loved having children. They expect perfection from her, and she tries her best to give it to them.
And then there’s Edric and Emira. On the other hand the twins, while certainly not unscathed from their parents, seem to be slightly more free from them than Amity. This is probably due to Alador, honestly, as he seems to see the same aspect in Amity now, too. Of course, this freedom is only an illusion, but they might not even realize that themselves. Amity certainly doesn’t.
But they don’t seem to have something like Amity’s necklace for themselves, and honestly, I doubt they even knew the true intents behind her own. And they don’t have one because they’re raised differently than Amity - because if the twins are left free to grow, they’ll be more powerful. Nothing would have come from them if they were raised like Amity; solitude wouldn’t work for them, because they had each other. So they’re let off the leash, so to speak - though again, that freedom is only an illusion itself.
Amity is smothered because that’s how she’s been forced to learn, and Edric and Emira are given a (fake) freedom because that’s how they learn. Alador and Odalia know exactly how to handle all three of their children.