Hello again and thank you for the additional information, it was helpful and I am sorry to read about this situation. You are under no legal duty to inform law enforcement or the dentist of what your wife did. Based solely on what you have told me, there does not appear to be an issue here of being an accessory either before, during or after the criminal
act. If you turn your wife in, she will be arrested and charged. She could be charged with either Federal or State charges, but in either event, they are serious charges and she would need a good criminal defense attorney to assist her.
That said, the only real concern that I would have is with your employer and the insurance claim. I am not sure who filed the claim, but since it is your insurance, even if she actually sent the paperwork in, you could be considered to be a part of that fraud if you knew about it. So, that would really be the only real exposure to being an accessory and also could ultimately lead to you losing your job.
I am not your attorney, since we cannot form an attorney-client relationship, so I can't tell you what to do, but if you were my client I would not generally recommend that you report your wife (and yourself) to your employer/insurance company. That ultimately could end things for you in the same way as if they find out through other channels. But you ultimately have to do what you think you must. Just be aware that it exposes you to potential criminal charges and loss of job.
Otherwise, if you believe that she will be able to comply with her treatment after Detox and won't do this again, then you may want to stay in the wait and watch mode. If, on the other hand there is realistic feeling that this will continue when she gets out, then you may want to separate your assets, etc., in order to protect yourself financially should she get worse.
Please let me know if you need any clarification. I would be glad to assist you further if I can.