My problem with Shadowheart and Lae'zel is the apparent assumption on the part of Larian writers that in order to be strong a woman must be unpleasant and constantly shout. I wouldn't mind one of the female companions being like that, but why both? This IS a hackneyed trope.
I find her so unpleasant and annoying, I don't care about her 'mysterious past'. I kill her and that takes care of that. I generally killed Sebille in DOS2 because anyone who wants to murder you for merely looking at them probably needs to be put out of their misery.
ETA: By the way, the OP knows damn-all about feminism, but it is not my goal in life to educate him or open his closed mind. Nevertheless, I do agree that a female companion at least close to the range of sane would be nice.