Out of Character

Yeah, that would only be 35 feet to get there if you didn't have to use stairs since you are flying.
That place is actually lower than the current platform. Here is a little visual aid:In an attempt to be clear, as it can be harder to do this over text than in person, here is what the heights mean:
the area with the 50 has 50 feet between it and the ceiling. It is the lowest point, and the water goes right up to it. If you fell in the water and didn't want to risk climbing over a wall to get back up (disadvantage due to being wet and slippery unless you have a climbing speed), you would have to go to such a place to climb out.
the area with a 40 is where you all started. 40 means 40 feet between floor and ceiling.
You are all in the area with a 30, 30 feet between floor and ceiling, with pillars going from floor to ceiling.

TLDR: Yes, you can make the movement. No, it is lower, not higher up. If you want to be higher up than everyone else but near the ground, you will need to go north near the throne, not south near the door. I'm assuming if you are going to dash (since your fly speed is 20 and you want to go 35ish feet), you are probably averting your gaze.

the movement was correct. She has a legendary action that lets her move up to her speed without opportunity attacks.

I did forgoet to move Kelnes, though. He is still grappled. I'll fix that