Be sure to wait for the first amended return that was mailed in to complete processing...you don't need the second amended return to land in a mail stack and get processed before the first amended return...or you'll have a bigger mess on your hands.

Do I create a second file for the second amended return for same year.   Do I create an second amended return using first amended return information?  Will I end up with original file, first amended return file, and a second amended return file for same year.