That's interesting. I played the coup a few different times but I never sided with Werden. I don't remember any scene that indicated that she was safe or got away. I think that it was because I helped her fall in love with the older orc chief in that playthrough so she made an appearance at the feast schmoozing Jezera. Would you indulge me and further inform me of what her fate is in that case? Is it similar to Juliet in that she is offered as a prize to Rowan?
Basically, there are five possible fates awaiting Delane:
1) Ulcro's (older orc chief) concubine;
2) orc sex slave (if you help Tarish or Batri);
3) Rowan's lover in Rastedel (if you rescue her and later side with Jacques or Patricia);
4) sex slave in Bloodmeen (if you rescue her and later side with Werden).
As you probably know, if you side with Jacques or Patricia, after the sack of Rastedel Jezera transforms High Priestess Marianne into a statue. But if Rowan helps Duke Werden, Marianne manages to escape from the city before it's concquered so Jezera never gets her. Twins are generally not in favor of Rowan siding with Werden and they later punish him by enslaving Delane and transforming her into a mindless sex toy right in front of him.
Actually, we don't know what exactly happens to Delane if Rowan rescues her and does not side with Werden. Jezera never brings her to Rowan like in Werden's route, so that probably means that Delane managed to safely escape from the city. I hope her plotline will be further developed in Act 2, because she is an interesting character and has some hot scenes with Rowan (especially that scene in Rastedel's inn).