One option you do have though (that WDW does not allow) is to bring in an outside photographer. If you google this, you can see many family sessions, engagement sessions, etc.
We recently did a honeymoon session there (and booked her for a family session later this summer because she was so fantastic. There are many photographers locally that will do this (so you can find the right fit for your family).
Pics here on my trip report (just our proofs, nothing edited)
http://www.disboards.com/showpost.php?p=44661165&postcount=40
and our edited ones on my FB page:
http://www.facebook.com/media/set/?set=a.10150736796667221.416098.748157220&type=3
Have fun planning! Hope you can find someone to do this for you!