Ask her that!

"What are you doing up there?" You ask. "Aren't you sick and at home?"

Lexi sniffs.

"I've still got the sniffles a bit, but I'm better than I was yesterday. C'mere dude, I want to take you to see a thing. And I can't grab ya through the metal."

She reaches out towards you and clasps and unclasps her hands, for emphasis.

"How do I get up there?"

"{if LexiWin == True}Don't you remember? Hatch in the room with all the computers. I'll crawl over and meet you there, if you're down.{else}There's a hatch in a room with a bunch of computers. C'mon, I'll crawl you over there. Just listen for occasional knocks on the vents above you to keep on track. What do you say?{endif}"