Cant find Barretta by the tomb

[tazzme83]

I am working on 3 stars of destiny and I think I may have missed a valuable item. i have gone through the marshland to Zen, and to Sankt Leona Northern lands to Sankt Leona. I found the 'big tomb' the first time thru the marsh and when i arrived, all Random says is "it's locked". I have read a few detailed walkthroughs and they all say I am supposed to see a blonde girl in front of the tomb called 'Barretta". I am not sure what i missed to make her not appear. I have returned to the tomb on several occasions to see if she has arrived yet, and no luck. I dont want to skip this part of the game so what do i have to do to fix this?

[Indinera]

You must have reached the end of the swamp before entering the temple.
The blonde girl goes away if you do.