wow... part of me says do it in person and part of my says it might be easier to express yourself in a letter.

just tell her that you made these decisions for her best interest and because being her father, you love her, even though you haven't been around to raise her. tell her that you know this must be confusing and that she might not understand and maybe she'll even be upset with you, but that fact that she is in good hands is all that matters to you.

ah... there's so much you must want to say. i can't even imagine being in your position but I respect what decided to do for your child