Her death certificate should at least list her parents' names which can be very helpful in identifying the right person should the date of birth be off which can be common. Also sometimes, and it is rare, the exact place of birth is listed.
Does her obit list any siblings? If so check their obits and death certificates. It was through my great-great-grandmother's sister's obit I found the town they came from. I've even seen the marriage record or death certificate of a child give the exact town the parents were born in.
If you've gone through all the indexes for Lower and Upper Alsace on the respective websites it might be that she was born across the border but possibly raised in Alsace.