I came across a PSIII message board that stated the following regarding Sari, daughter of Lena (should you choose Ayn's path):
If Rhys married Maia, Sari will become the daughter of Lena. Sari is very upset
at Rhys for marrying Maia 15 years back, and thus doesn't like Ayn one bit.
The marriage of Rhys and Maia left Lena alone, and is believed to have died of
heartbreak, thus leaving Sari to become Queen of Landen and Satera. This is interesting, isn't it? Why would Sari be "very" upset?
Would she not exist if Rhys marries Lena? By the above statement, if Rhys marries Maia, Lena is left alone,
and is so heartbroken she dies. This leads me to the following theory:
What if Rhys is Sari's paternal father? As the audience, we have no idea who Sari's father is, or if Lena married someone else. From the looks of it alone, Sari is about Ayn's age. If Lena was so in love with Rhys (as she was), isn't it hard to believe that she'd jump into bed with some other man?
What's also fascinating is that Sari becomes queen of
Landen. How is that possible? What, exactly, were Lena's ties to the royal family of Landen that would prompt her daughter to inherit the land? Again, it's the thought that she is the daughter of Rhys.
If this is true, though, this would make Ayn marrying Sari a total ick factor, but then again, royalty marrying a cousin or a relative of some form isn't unheard of.

Still, I'd like to hear some opinions on this theory.