Remember that transcribers of records are supposed to copy a record or a source the way it is written--not what the record "should" say. If grandma's name is Susannah and her marriage record lists her as "Susan," transcribe it as "Susan." If grandma gave the wrong place of birth on her marriage record don't "fix it" when you make the transcription, copy it as it is on the record.
You can (and should) make a notation somewhere that the information is incorrect, and state how you know it is wrong. But don't edit and correct what was on an original record.