Well worth asking a lawyer, because they know some ins and outs. My wife and I did this after our first child was born. It was a few hundred bucks to get wills, general powers of attorney, and healthcare powers of attorney for both of us. (Our situation was simple: leave everything to each other or the kids if we both kick it, and designate a guardian for the kids). We'd have gotten living wills but haven't decided what we want them to say.

The lawyer put in a bunch of things we would never have thought of, e.g.:

Making the will sibling-proof (it divides everything equally amongst all children we might end up having, which turned out to be 2)

Waiving the requirement that our out-of-State executor post a bond

Authorizing the executor to open safe deposit boxes and the like