I think that all pre-2005 tickets are park hoppers (the exception being the 1-day/1-park passes or 2-day/2-park passes).
If your friend has a PHP (park hopper plus), her pluses are good at PI and the waterparks. Her pluses cannot be used at DQ.
For admission to the parks, she should just insert the ticket before passing thru the turnstiles just like she did before and then she will need to do the fingerscan like anyone with a MYW pass would. She does not need to trade the old pass in for a new MYW pass.