Before saying that I'm a little crazy, let's think logically.

When the main character killed all the goblins and got to Minthara, leaving her with low HP, she will understand her defeat and will not want to die. This should trigger a cast scene in which she asks why we are doing this (and will be forced to find out about the tadpole) and offers to save her life as a captive / companion in exchange for answers to the Moonrise Tower and help getting there. Yes, it will be a trap with a very high probability - in any case, it will be her motivation initially. But this can lead to the fact that she can find out the truth about her goddess Absolute, which she will not like. Then she will have no choice but to move with us if we save her life again, and rethink her behavior - all the more, in addition to the absolute, she has a problem in the form of Lolth that she betrayed. Perhaps this could make her more neutral like Viconia, in BG2 there was such an option. Anyway, no more evil than Laezel and Astarion. Eilistraee's clerics could help.

I do not want to kill Minthara in the second good playthrough playing as a high elf or drow Eilistraee, like many of those who will make the first playthrough on the path of evil - if on the path of evil she perfectly reveals herself as a character. But replaying her romance in a completely different way (more difficult) is a very, very cool idea that can motivate me to try the good way without feeling upset.

I think if given such a choice, many of those who like to play on the path of good will have the opportunity to see Minthara content, learn more about her personality, and the work on writing this character will be appreciated by more players. To spare the life of the enemy who surrenders is a good deed, attempts to "re-educate" Viconia in BG2 were also very popular. Even if it doesn't work out completely (she's too evil), it's still interesting.