How to get Yrliet Romance ending?

I finished the game for the first time and realized i missed some stuff so i decided to do another walkthrough, i found out i could romance Yrliet so i decided to take that route cuz i found it interesting, considering Eldar - Mon-keigh relations. I checked the guides on how to do it and supposedly, it should be completed after she invites you to her spirity world before leaving through the warp gate. But in the ending she just becomes a pirate.Is there something else i might ve missed because i feel like i wasted that second playthrough.