When you side with the Mages, you can find Fiona in the Library
next to Dorian
who shares the same name as the Orlesian Noble who sexually abused her when she was younger
and both Dorians owned slaves when Fiona herself, from a young age, was a slave (specifically a slave to the Orlais Dorian who sexually abused her) before coming into her Magic.
Like no doubt she suffers from PTSD from being a slave and an abuse victim so the developers place her in the same place with a slave owner with the same name as her abuser?
Dorian doesn't fit the personality of Fiona's abuser, besides not even being from Orlais.
But, besides technicalities like that, in case his name wasn't picked at random, I think there could be a better reason for Dorian to be meters away from Fiona (if you side with the mages.)
From my own experience with PTSD and other issues (that are absolutely unnecessary to mention,) sometimes it's actually therapeutic to start relating triggering factors from the past to new, pleasant, and harmless things/people/words/names/places/etc. It's an effective way to overcome such issues, and it worked wonders for me (though it takes time, of course.)
So, maybe, Fiona and Dorian being steps away wouldn't be bad for her at all. She could start relating his name to someone pleasant that seeks to end corruption in his homeland, and that sets a good example of what a mage (and person) should be, instead to someone that hurt her beyond words.
Dorian could actually be helping her heal unknowingly...