I wrote this in other thread, but it applies to same question, so I decide to take this part of the post here as well.

- Minthara if looted, just like companions loses all the equipment and the change is visible on the model. (loses the shield/armor/weapon)
- There is an romance option for her. (currently only an option for companions, might change in the future)
- Has a tadpole in her head, just like rest of companions so far, while still having possible friendly-ending interactions which hint further co-operation (this might not be true in the future).
- I have read that in game files one of companions in hinted to be a drow.
- Wiki displays her as a potential companion
- Probably will be possible to recruit late act 1/early act 2 if she survives, won't be possible to recruit as soon as others
Above for drow companion, with a bit of other information regarding possible companions, one of them being the poor unlucky windmill gnome.
Link for wiki is above

Seeing the positive reaction of people both towards her and Halsin, besides those things mentioned above, makes it even more likely.
As for the conflicted nature, while she is definitely (initially) an evil character, she does have a potential to either become someone better or even worse than before.
If you do the romance story with her,
You can deduce that the whole party and the spending the night together part was her just being sent to kill the Player Character, homever she can't really bring herself to do it (100% success persuasion check, even without tadpole power) and reacts in completely opposite way, selflessly helping you, while putting herself de facto in a tough situation, would you want to expose the fact that she did help you. When someone taught since early years to not trust anyone, living in danger and without any real friends for years and apparently liking prestige, power so much decides to help you, in such a way, you know that there is someone else under all of this persona shown to you. Even if it's deep, really deep inside and it if it takes time for it to show.

In older Dungeons and Dragons game, Neverwinter Nights:Hordes of the Underdark, you could have a drow companion - Nathyrra, who was a redeemed Red Sister (elite drow assassins sworn to serve the Valsharess). She also, until a specific point, was definitely evil character, until something broke her (in that case, the mercy and the good of the Seer). We need to remember than many of the drows act evil simply because of how big impact their society, upbringing and religion has on them. They aren't born merciless and traitorous. If someone dedicates to show them that they can be better, resulting in a huge change (or they can become even more evil, obviously it's not one sided).

So there is sense for her to still survive the "good" storyline. If we have an option to spare her after the siege battle.