I have heard some (some!) of your story over the years, as an avid user of Behind the Name. I offer my sincerest condolences for everything that you have went through, and if you ever need to talk...I am here (I have PTSD myself, regarding childhood trauma...not like that makes me any more trustworthy, but I just wanted to offer support). I do hope that writing this memoir helps you comfort these deep, hurtful wounds. Personally, I love to write, and it's one of my coping skills for PTSD...it tremendously helps me to apply myself (somewhere) in my stories.
I'd like to preface, that I do enjoy some of these names...so, I'm not saying that I think of "nasty women" when hearing these names. However, I think that they could fit your sister, based on the description I've heard.
Claire (or maybe
Clarice / Clarise and
Clarissa)
JoanneIsabella (Also
Isabel or
Isabelle; this is after your sister's favorite Disney princess, and I know redheads with these names.)
MichelleValerieDeniseNicolePatriciaTamaraTeresa /
TheresaTamikaEllenJacquelineBrianna (I also love the name
Breann, and think it could suit your sister...but the spelling might be too complicated for your taste!)
LillianMaxineDoreen (though I do prefer the spelling of
Dorine!)