Similarly, did Shadowheart chose to be Sharran? No. Does she know what Shar truly stands for? No.
Where are your no's here coming from? I see a SH who knows exactly what Shar is about and chose to become her faithful. But, for the sake of argument, if SH tries to claim 'no,' per your claims here, why should I believe her? Claiming to have been "brainwashed" is exactly the kind of bullshit a Sharran would claim!
Have you actually played EA?
Shadow stait up tells you she only remembers 2 things about herself.
That she can't swim and that she likes night orchids.
We know she's telling the truth due to the tadpole.