I didn't take away from it that she died. I really didn't.
I actually thought it played out more like this above only less scornful. From 'Until We Sleep' #2, it sounded like Bartrend was hunting down his little brother to continue being the middle man, given that we know, in DA 2, he had a lot of connections in the Cartel. I thought Varric voluntarily went back to Kirkwall because his mother died, o something, and Bianca was forced to go off alone. Or was forced not to show her face in Kirkwall again.
. Didn't the people making his story say that she was suppose to be a Chamber Maid for his mother? Was that how they met? Heh, I always thought she was going to be part of the cartel or something.. Hellfire be it, if House Tethras would have him marry a common surface dwarf let alone a servant.