sorry to say this, but I agree with your sister. Taking the high road should not be the goal at any cost. Let things evolve and keep walking forward (while you walk through hell, I know). You deserve a lot more than this woman is capable to offer at the moment and I hope you recognise this and act accordingly.
It's not easy for me to say this but I believe you should let it go. Completely. Whatever you do, do it for you and your D. Take her out of the picture. The woman she has become should NOT be an option for you. You deserve much better my good friend. Much better.
