Calpernia is the straight female love interest for DA 4.
It is known.
I was surprised that this topic didn't come up earlier in this thread. Here's my take on it:
Most of Bioware's romances have the fundamental problem that the romanceable characters are companions, i.e. they feel subordinate to the player character. The DA games have been much better in counteracting that effect than the ME games, but it's still noticeable enough that most romanceable characters don't feel quite like the PC's equal. So, yeah, I would rather like to see what a relationship with someone like Calpernia is like, but she should never become a companion. Whether rival or ally, she should be equal in stature to the player character. Undoubtedly that would make the majority of players hate her, but then there have always been romances that appealed only to a minority. I would also hate it if a romance compromised her character, for instance by making her change her goals to something more acceptable from the viewpoint of the feel-good morality Bioware so often employs in their stories (again, less in DA games than in ME, but still prevalent).
Bioware did one romance which was excellent in this regard: Morrigan's. In DAO, she had her own goals and wouldn't compromise them for the romance, and when I met her again in DAI, and she talked about "her" Warden, it felt completely natural and "Morrigan-like". She also came across as matured without having turned into a "nice girl" type. I would like to see another one like that, but not every writer is able, or willing, to make one.
In the end, all I know is that I would like to see Calpernia again in a future game. As herself, i.e. not changed more by implied character development than Morrigan was between DAO and DAI.