I'm getting a bug in SOD where Sirene will say something and then the conversation will end once I click "Continue". I had a similar problem with Roxanne's Sandrah companion in SOD, and she gave me a hotfix which fixed the issue.
Pure speculation (probably wrong): This is quite possibly down to the mod which turns the SOD 'overhead' banters into traditional, textbox ones.
Great companion, by the way. Plan to take her with me everywhere regardless of this bug.
Is this BGEE/SoD or EET?