I don't think there's such a word. There's simply very few contexts where you would need to consider both widows and divorcees as a single category, because other than being previously married they have very little in common. Maybe in previous eras such a term might have been useful, since unmarried women were considered incomplete, and both would be eager to find a new husband. But in modern, western society this isn't the case.
Also, in those earlier times I suspect divorce was much less common -- it's only in the last few decades that it has lost its stigma. So in earlier times most members of the category would be widows, and divorcees were considered tarnished, so people wouldn't treat them similarly. So again, there would be little need for a common term that encompasses both.
If you need to refer to both situations, you'd simply use a descriptive phrase like "formerly married".