You most definitely have my sympathies. Situations like these are heart-wrenching.
But it sounds like you recognise that it's not going to be, because of her own wiring and boundaries. You are being realistic.
It hurts, but isn't it better to feel such a powerful thing, and sometimes have it hurt, than to go through life never feeling anything at all?
Please check out The Birdcage - an open, friendly Polyamory forum for all parts of New York State
"Listen, or your tongue will make you deaf." - Native American Proverb