At the end of the book there's an FAQ. (Free advice to academicians: do this more often!) One of the questions is the thorny issue of the role that the Mosaic law plays in the life of the Christian. Here's how she concludes the dicussion:
In sum, I think we can identify at least three categories of Mosaic law which, in their specific expectations, no longer apply to the Christian: those involving the regulation of Israel's government, those involving the regulation of Israel's temple, and those laws that the New Testament specifically repeals or changes. I would still argue that the values that shaped these regulations express the character of God and therefore must be attended to by the Christian, but the specifics of their application are no longer our responsibility. Thus my contribution to the conundrum named above is that rather than attempting to delineate the law of Moses based on categories foreign to that law itself ("moral/ethical" and "civil/ritual") perhaps we should address the question through a lens that is more native to both Old and New Testaments--Jesus' redefinition of certain major institutions of the Mosaic covenant. And for all the Mosaic law, be it superseded or not, we need to recognize that we can (and must) still learn a great deal about the character of God through these laws, even if we can no longer directly apply them to ourselves in this new covenant. So rather than thinking in terms of the Mosaic law being obsolete except for what Jesus maintains (as has been the predominant view), perhaps we should begin to think in terms of the law being in force except for what Jesus repeals. [pp. 228-229; italics mine]Undoubtedly there's much more to be said, but I think this is a helpful way to put matters.
I've mentioned this before, but if you're looking for a relatively concise survey of how the NT treats the continuity/discontinuity question regarding the law, a very helpful book is Frank Thielman's The Law and the New Testament: The Question of Continuity.
