I'll make a quick note: The story of Via x Feros is highlighted and considered exceptional because they had a relationship despite being of different legions. There are rivalries between the legions, and it's usually obvious which legion affiliated fahrar a cub will go to. From Blood parents to Blood fahrar, etc. Though, if it does happen and both parents are in touch or surviving, they'd likely be pragmatic and decide together (or fight it out).
If anything, Via would've been expected to take her cub to a Blood fahrar - but she has emotions, so.