I think honestly, the whole train can feel like a cell to me.

[Sure the only difference between the train and her tower was the fact there were people and more things she could actually do. But she still felt that sense of being trapped when not on missions... and she wasn't on the last mission so it's been a while since she last stepped off it.]

But yeah...it's hard to find areas of quiet but... the train has taken requests before, so that's always an option. Might not be right away, but you never know. I can even ask too if that helps? More voices the better.