That sucks, to be certain. I was rear-ended on the freeway a few years ago and the damage didn't look bad on my '73 (posted pics way back when) but her car was totalled. At least in your case the woman that hit you has insurance....the woman that hit me was uninsured and undocumented. In my case it took about a month before my insurance company made the decision to fix it (full coverage policy) and the body shop was very helpful in providing comps and a pre-accident estimation of the Bronco's worth. They did use auction Broncos, and their selling prices, for some reference, along with other listings that they found to be comparable. They didn't trust my valuation. I'd say, from my experience, definitely consult with a lawyer and don't try to take her insurance company on yourself; if your insurance policy/company helps along those lines all the better! Also, make sure that the repair shops do what they can to check the frame and the entire rear end....these things are stout but a hit like that could definitely have tweaked things a bit.
It took 7 months and a whole list of other hassles to get mine back so I feel your pain and hope that everything goes well for you!