I agree with farmergirl, sit this one out. It willl only complicate things for you in the long run and it really won't satisfy any of your conflicting emotions. It could actually be a bad thing for you to see her in another setting where she is not there solely for you. You need to maintain the image that your T is yours and yours alone during your treatment. It could hurt you to see her with others who love her.
I also don't understand why she is your friend on Facebook. That could be a potential danger spot too.
I know how curious you are, I'm the same about my T, but just resist the temptation. It's not worth it.