She might have found some sort of a map or something leading to the location of the Fort.

If the helicopter Kalani flew was military grade then a map or something could possibly been able to survive in one of the compartments, unless of course the entire helicopter was blown to smithereens. If thats the case then she might have been able to find a map in one of the failed escape cars or maybe in the ruins of the tower.

Going out on a limb here I know, but it didn't seem like she was that interested in the person she found on the ground, she wants something more useful to her.