So the latest revised Ivora and Valla background goes as this: 

No one knows what type of troll Ivora is, nor just what she is capable of. It’s obvious she knows powerful magic, but to what extent? The fact she can shapeshift so flawlessly alone is unsettling to most trolls. Ivora herself, while very self-taken, hates that her shapeshifting abilities are limited. She can turn into any animal, sure, but humans? That’s proved more difficult. After trial and error so many times, she came to the conclusion it was unreachable, even for herself. But, perhaps her successors could achieve it?  This is how she came to court Gunmar, which wasn’t hard at all. Gunmar is smitten with magic. A few magic tricks, and you’ve got his attention. Plus Ivora fit the Gumm-Gumm lifestyle well, except for usually avoiding battle. Not because she wasn’t able to cause havoc, but because she had better things to do. Gunmar was, after all, born from the bloodshed of terrible war, a Heartstone crystal poisoned and birthing him. Ivora hoped that if her own heartstone was combined with his, and she secretly tampered with the yet hatched whelp, she could achieve ultimate shapeshifters. 

The first attempt resulted in twins, who greatly resembled their mother and were naturals with magic. Ivora couldn’t have been more pleased. The second attempt resulted in Valla, whom Ivora considered a warning that maybe she should invest solely in the twins. Valla had magical potential, but not to the same degree as her sisters. Plus she resembled a more balanced mix of her parents, which sickened Ivora. The third attempt wasn’t even a real attempt. Gunmar was vocal in wanting a son, so Ivora humored him with a third try. Bular was hatched, a mirror image of his father. 

Needless to say, Ivora took the hint that her experiments were over. 

It had been great, having trolls to hunt for her, keep the pesky wizards away, and flatter her endlessly, but Ivora had bigger fish to fry. She didn’t waste her time,  telling Gunmar exactly what she thought of him: an idiot, a waste of rock, only good for basically crafting material. She abandoned Bular, but took Valla, along with the twins, vanishing before Gunmar could do anything. 

The twins had been near preteen troll years when all this happened. Valla had been much younger, and Bular basically a hatchling. So the twins remember their father and brother well, but for Valla things are fuzzy. She definitely remembers that her father and brother were more like her, but that’s where it ends. 

Valla was raised to be the servant, basically. She hunted for her mother and sisters, kept their quarters clean, fetched whatever supplies or ingredients they needed. While she showed talent, Ivora refused to teach her magic. “You’re place is as the hunting troll, not a witch.” Keep in mind Ivora was never out right hostile, but passive aggressive- think Mother Gothel. 

There is much more to tell about Ivora’s research, but that’s for another post. To finish this long info dump, let me answer the obvious question: What did Gunmar think about his other children? He loved them. It stung that his eldest two daughters were quite distant, even as whelps. They had their mother’s high and mighty air, and always rolled their eyes whenever Gunmar tried to roughhouse or brought them fresh bones to teethe on. Valla was different. She was bigger, rougher, and, when Ivora wasn’t around to guilt her away from it, she happily roughhoused with her father. When Bular came along, she and him were inseparable- Valla wasn’t all that big yet, so Bular could chomp at her and actually spar with her, even as a hatchling. 

However, that changed when humans began to lurk closer to her forest lair, especially wizards who had grown tired of her luring in their apprentices, which never came back. Gunmar took this opportunity to introduce himself, and offer his protection in exchange for her magical assistance. Ivora had no choice but to accept, as she could have handled the problem by herself, but she didn’t want wizards to know truly how far she had come in terms of her magical might. Better for them to think she’s nothing but a meddlesome, lucky troll who got good at ordering in snacks. 

It’s my personal headcanon that Gunmar is a sucker for magic. He isn’t blindly enthralled by it, he knows to be cautious, but it mystifies him all the same. It can bring incredible power, after all. So naturally he became very taken with Ivora, who absolutely did not return the feelings. She was, however, very interested in Gunmar as a study subject, considering his origins. Ivora falsely returned his affection, if only to get closer to study him. This even gave her the opportunity to combine her heartstone with his multiple times, each whelp produced inspected closely by her. 

Eventually Gunmar saw through her guise, mostly thanks to him watching her take no effort whatsoever to be a mother, or even a responsible adult troll, towards their whelps. When confronted, Ivora’s pride was hurt given that Gunmar, who she considered an idiot, could have figured her out. She unleashed her magic on him, paralyzing him long enough for her to scoop up their whelps and melt away into the night. 

The only whelp left had been Bular, who was naturally more feisty than the rest of his sisters. He had squirmed and fought too much for Ivora to really care about taking him with her. Besides that, he was the whelp that displayed little to no magical promise out of her entire brood with Gunmar. So he was discarded as soon as he started kicking back at her.