To me this is something different in each relationship. And one thing I think, that made it easier on Karma was to know these boundries would eventualy change.
Currently our boundries follow our rule of "Happy, healthy and sane". And this is for all parties involved. In the begining the boundries were tight because Karma and Cricket were both trying to rebuild trust with me. I needed to know I could trust them. Individualy and as a couple. So the boundries, or rules as we called them, were tight, no seeing eachother without me there, physical contact was limited, phone calls and e-mails were subject to me being there. No hiding. To me they lost the right to privacy when they had the affair. As the trust grew, I pulled back on A LOT of that. They were allowed to drive her home without me there, they were allowed to go to a friends house without me, I stopped reading every e-mail, I encouraged physical contact even sleep overs (though I had a hard time with that as I pushed it a little too soon), and we instituted the 24 hr rule, as long as I had 24 hr notice, they could have visits without me. Eventualy, it became only about respect and safety.
Our boundries now include honesty, respect (do I have plans, am I feeling okay, and me respecting them and their plans), and safety. Happy healthy sane as we call it, as long as we are all happy, healthy and sane, it's okay. If not, then it's required to sit down and find out what the issue is and how to fix it.
So after that long explanation of where we are, my question is, what boundries are you setting that she feels are getting in the way of who she is?
As it was said by someone else, if they are your NEEDS then they need to be respected, but you also need to respect hers.
Compromise is a huge part of making this work. I believe in compromise, not saccrafice. I think if compromise and communication is an issue, it's time to analyze your relationship as it stands.
Karma and I are far from perfect, but communication and respect of eachothers thoughts and feelings has made all the difference in making this work.