First off, this may be a possible mod conflict.
The two mods I have that alter Tatooine in any way are Tatooine Job Office
Basically, I meet Malare and her and Bastila have their talk about Helena. Then the one alien tells us that Helena is in the Cantina on Tatooine.
We get to the Cantina but NO Helena. Now I tried to fix this but decided it wasn't a game breaker so I decided just to play on. So I am hoping someone can help me fix this for my next playthrough.
I have only just left Tatooine in my current playthrough so it may still be possible to fix plus the quest is still in the game journal.