UPDATE:
The prosecutors have brought charges in one of the seven cases of 'violence in close relations' that have been under investigation. This means Gjert Ingebrigtsen got cleared of quiet a lot, but on the other hand, the charge of 'violence in close relationships' is more serious than the one pinned out originally.
Even though the name of the sibling in question hasn't been reveiled, they might as well have due to what's come to our knowledge:
- A younger sibling of Henrik, Filip & Jakob leaves us with 2; Ingrid (18) and William (10). Their mother, Tone, is still leaving with Gjert, meaning she hasn't been given the ultimatum to move away from Gjert in order to keep the youngster, -witch leaves us with Ingrid.. Which we already knew due to the news of her having left the sport being dropped in the same article where we first got to know about the split between father and sons.
It has also been confirmed that the insident that set the whole thing off, was Gjert (allegedly) lashing out with a towel, leaving her with a red mark on her face.
According to (alleged) witnesses, Filip was seen driving in high speed to her wereabouts to pick her up, where he assumably brought her to the home he's sharing with his wife and daughter. This is, as implied, not officially reveiled facts, but the fact that it's been told by several witnesses, as well as her reaching out to Filip kinda adds up with the bond between the two that comes through in their TV-show makes it worth mentioning.