My impression (admittedly including some theorizing to try to fill in some blanks) is that Lena's gone through enough inner turmoil and worldview shift since last season's end (Lex, Eve, Kara, everyone?) to keep a therapist busy for years, and her fundamental approach to how to help humanity with her technology has changed harshly as a result, and that the writers haven't done a very good job of showing us enough of that to help us understand and sympathize with Lena's new point of view.
@minibutmighty - Totally agree with Thogek (previous commenter). Although, we have certainly been hearing enough from Lena herself about how untrustworthy the people in her life have been... so personally I can see how that could drastically affect someone whose core values are founded on truth and trust. I don't think she's overreacting, but the writers definitely haven't done a good job of adequately showing us what they've instead been telling and that is indeed bad writing.
@minibutmighty AGREED 100%. But then, I guess she is a Luthor, so that is how she was raised; to keep grudges, unfortunately.
Shout by MiniButMightyBlockedParent2019-10-07T22:45:25Z
I think Lena is overreacting. Kara confessed and apologised, what else does she want? I don’t like what the writers are doing with this story. Everything else was greath though and Katie McGrath is perfect as Lena.