The Verdict: Not eligible
Citizenship through this marriage is closed, because the law requires the marriage to be continuing when you apply.
Under Article 16 of the Turkish Citizenship Law and Article 25 of its Implementing Regulation, an application is not accepted if the marriage ended by divorce or by the spouse's death before it was made. Only a death after the application keeps it alive.
If you live in Turkey, naturalisation after five years of lawful residence is open to you on your own account, and our naturalisation quiz covers it. Any children of the marriage are Turkish through their Turkish parent; our descent quiz covers registering them.