Why are some registrations duplicating, but not identical?

We've had four families register with duplicating records.  I called one of the families today to see if she was aware and if there was something I could do to help.  I understand that the duplicates were caused by phone registrations where the site froze and the registrant hit "enter" a second... or third time.  I understand that... but why would the duplicates not be identical?  Each of those registered as a girl, the second entry defaults back to boy.  Hopefully we won't have a lot of these, but a second aspect that is difficult to manage.  The listing of students where I can manage students, doesn't include the sex of the student, so it is more difficult to determine which one needs to be deleted. Would it be possible to include the sex on the manage student page?  That may also help me when reassigning classes.  Thanks.