Law firms can be difficult to value. You have to take into account the hard assets and the practice sources for immediate revenue.

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.