I play Bronwyn and since SHARK has shared with me that he posted a thread about this situation, I thought that I should put in my two cents.
First, let me address some of the questions regarding the campaign in regards to religion and a code of behavior. for Paladins of this deity. In the campaign the deity that Bronwyn worships is a god of war and strength (among other things). This deity is worshipped by various human tribes and kingdoms (including Valloreans, but Bronwyn is not Vallorean). The deity appeals to martial societies and people. This deity has some differing tenants based on the home culture of the worshipper. Bronwyn's culture is a largely rural, feudal society, slightly more advanced than a barbarian tribal culture.
This society does not hold to a strict monogomous ethic, in or out of marriage (although members of the culture may) and this remains true of the deities worshippers. Sex before marriage is not frowned upon and would not be considered a breach of her Paladin code in her home culture.
SHARK left out a couple of salient points to Bronwyn's behavior with Ghandethar. Ghandethar defeated her in hand to hand combat and knocked her unconscious and carried her away rather than killing her outright (which he could have done easily as he is considerably more powerful than she). When she came to, he made it perfectly clear to her that she was his prisoner and that he would make her his slave and hunt down her party if she was uncooperative. Bronwyn at first did not respond to him but did not fight him either. As she did not fight he began to be kinder to her. Eventually they came to a mutal admiration of strength, wit and determination. At each turn she attempted to show him the virtues of her deity. She figured since she was in this position she should gain all the information she could to further the goals of her party. She did not give information that would jeopardize her party.
Ghandethar kept Bronwyn for several weeks, in which she came to respect and care for him as a person. In that time she did not witness him committing any evil acts (although he illuded to acts he would commit if it became necessary). For those of you who know about SHARK's campaign, detect evil is only usable if the spell is cast on the target that has immediate evil intent. A target just standing there buying groceries, would not show as evil or not.
Bronwyn was not engaged to Vandor at the time of this affair, although she was sexually involved with him. In fact, there was no discussion of a monogamous relationship between she and Vandor.
As for the lying or not telling the whole truth about her later encounter with Ghandethar. Bronwyn knew that if she had told the truth, the party would have immediately sought Ghandethar out and killed him. He came to Bronwyn alone and mostly unarmed because he wanted to see her.
Rhiannon