It's too high for the girl to simply stand on your shoulders, so you face a rather difficult climb with her clinging to your back. She doesn't weigh much more than your pack, but the weight distribution is not the same.
After a few exhausting minutes, you are able to get the two of you high enough that she can reach the crack and pull herself through. You watch for a moment as she disappears, to see if she might throw something down to help, but nothing comes. You can only faintly hear as she crawls away.
Sliding back down, you listen again at the rock and can still hear the lizards. You can only hope that she returns with weapons so that the two of your can fight your way out, but that's even assuming that the crack leads to another way out.
It is several painful hours as you wait in silence. Your hunger has begun to gnaw away at you, and you've come to the grim resolution that the girl is not coming back, and you'll probably die in this room.
Then, without warning, the stone rolls away and the little girl walks in and gives you a hug. You look at her with astonishment, then out the opening, where a group of a dozen heavily armed men stand over the dead lizards that had been guarding the entrance.
The group wastes no time, you all quickly and quietly head down the tunnels, with the girl leading the way. She has an uncanny knowledge of the tunnel systems, and in very short order you find your way to warmer and better lit tunnels.
Finally, at one split, the girl stops, looks at you, and points. To your left is a straight narrow passage, at the end of which is a prick of light, suggesting it is a way out for you to take. The guards pause a short distance down the passage to the right, which is the way the girl will go as well. The girl waits, letting you decide which way you want to go.