The Arbiter had already informed these two about the proposal that Elena had. Previously, the Arbiter herself was definitely against it because of the danger that was associated with the whole plan but after seeing how incredibly capable of Elena was, she had started to think that this was actually a feasible plan.
So just like that, two new mighty people also joined in the meeting. But only one extra seat got occupied. And the reason for that was because the Accessor had decided to sit on Elena's lap instead of any chairs.
Elena was actually very happy about this and while her newest cute little sister was sitting on her lap, she was continuously patting her head.
So the discussion continued in this fashion for some time and at the end, Elena was able to make everyone to agree to her idea.
