Federal Student Loans
Federal Student Loans are discharged with the borrower's death, regardless of who co-signed the loan.
PLUS Loans (and Parent PLUS Loans)
PLUS loans are discharged on the death of the borrower. In the case of Parent PLUS Loans, if the parent(s) out-live the student, the loan can be discharged through the Death Discharge application. (Parent(s) may be subject to Cancellation of Debt Income (CODI) tax liability. Consult your local tax professional)
Private Student Loans / Credit Cards
Private loans and credit cards are not required to discharge debts upon the death of a borrower. Depending on the lender, they may attempt to collect against your wife's estate (community property) and you may need to seek out an estate lawyer for more specifics. My research shows that banks will often evaluate each on a case-by-case basis, depending on the amount of the debt and the assets.
I can't find any references about spouses living in separate states, at least for property law, and each state has wildly different laws. So depending on the amount of private loan and/or credit card debt, you may owe that (and want to pay it to avoid legal fees), but if the amount is quite high, you should consult an estate lawyer.