How do you determine the value of a law firm? This particular one has a $1.4 million dollar contract with the county and also gets private referrals.
However, the valuation for divorce purposes may be different from a valuation for business-sale purposes because. as a non-attorney (I'm assuming), you cannot be an owner of her practice.
In addition, if she is a sole practitioner, there's no business without her active involvement. Speak to a divorce attorney and a professional services valuation specialist to get the guidance you need on how to handle the financial issues between you and your wife.