Melissa was nowhere to be found and for some reason since I took Karl's journal early, the quest was saying the Khans were leaving the area rather than joining up with Caesar or NCR. I had to kill Papa just to get the result I was looking for....
melissa is right near quarry junction (the area with all the Deathclaws)
you have 2 options to reach her
Option 1: head over the the makeshift Khan encampment (just follow your map as directly at possible, you will see a few cazadors then what loks like a ransacked small camp site)
from here climb up the mountain kill a couple deathclaws and young deathclaws then walk into quarry junctions back door and there you will find melissa (it took me awhile to actually get to her)
Option 2:go to the mining town(the one where they warn you about the death claws if you have been if you have already been here great if not you have to walk(if memory serves correctly its a little bit north west of black mountain) (if this is your first time here a guy in the road will stop you and explain about deathclaws, you can also get a quest from him and another quest inside for a deathclaw egg
anyway moving on head slightly north from this town and then go west into the dusty area filled with many deathclaws.
to get to melissa from this path you will have to go through a mother deathclaw and an alpha male deathclaw.
hope this helps you all find melissa gl