First, let me tell you how sorry I am for the situation with your wife. I will certainly keep you in my prayers.
Yes, these are really the only documents you need to make sure are in proper order. The first 3 deal with acting on her behalf while she's alive; the Will deals with her probate estate upon her death. It's important to realize that certain assets pass outside probate and thus are not governed by the will and thus do not require probate. These include the following: i) joint brokerage and bank accounts which vest automatically in the surviving owner upon the death of one owner; ii) real property held as joint tenants or tenants by the entirety, which also vest automatically in the surviving owner upon the death of one owner; and iii) assets with designated beneficiaries other than the estate such as life insurance and retirement accounts.
With respect to the first 3 documents, you can simply use the same format and make the changes that are necessary by doing new documents. On the will, there is no need to re-do the entire will. Rather, you can make this change by doing a Codicil...which is a fancy legal term for an amendment when a will is involved. In the Codicil, you can reference the original will, state that other than the changes in the Codicil all terms and provisions of the original will remain in full force and effect, and then specify which provisions of the original will are being changed. You will want to have the Codicil signed, witnessed, and notarized in the same format as the original will. Then, make sure you keep the Codicil with the original will so whoever gets the will at your death will know the Codicil exists. You can do this yourself or you can seek the guidance of a lawyer, but you are not obligated to engage a lawyer to do this for you.
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