Kita - you are a little unclear on if at fault pary has offered you the policy limits for settlement or not. You say the their policy limits are $100K, but you don't indicate if this was offered to you.
Unfortunately, "We consider the injuries permanent" and "We feel it's worth more" are not arguments that have any legal basis. Has your attorney sent you to see an expert witness and get their evaluation/diagnosis indicating what future limitations are with the injuries sustained and what medical care may be needed in the future? This will help indicate what is permanent and what is not. For example, while your wife may not have recovered 100%, how much has he recovered? 30%, 50%, 75%? This will also help determine what the permanent injuries are. Is she still in therapy, or has she progressed as much as possible from therapy?
I can relate. I was in a head on collission (Nov 06) where we flipped and rolled and my wife was severly injured....broken neck, lumbar vertebrae, pelvis, arm, foot, etc. Almost $200K in medical bills and still going. I have learned alot about the insurance process and working with attorney's. When was your accident? The settlement process can take a while even when everything is clear cut (as in our case).
I don't know the contract you have with your attorney, but any expenses they pay out will come out of the settlement too. For example, if you go to trial, there are many more fees that will reduce your settlement. Even if you win a higher judgement than the $100K, if the at fault party has nothing to go after, the insurance will still only pay out up the policy limit, but you will pay many more fees from expert witness's and such for the trial.
Consider your options carefully and make the best decision with the information you have. Remember, no one will look out for you as much as yourself. Good luck.