Get your hands on park maps ahead of time and study them so you don't spend so much time doing so in the parks.
Epcot Characters on Holiday is a fun way to see lots of characters at one time.
PS's are a must -- even if you don't end up using them and need to cancel them... it sure beats eating at the food court all week.
include the kids in the planning or at least take their interests into account.
Meet Peter Pan at the MK.... my new favorite tip!
Explain the fast pass system to her and encourage her to really use it.
Have her buy her tickets BEFORE she gets there (but not from disney.com -- either do by phone, use
AAA or one of the trusted ticket brokers).
Measure her 5yo and find out if there are any rides that s/he will be limited to and come up with a plan to handle that before getting there.
Autograph books (maybe... I like this idea but I also found that w/o the books, we got better character interaction).
throw away cameras for the kids to use.
variation on the souvenir thing... if budget allows... let kids get one thing at the end of the day each day (or the last time you are at each park) -- will end up with 4 momentos. not too bad... some people have said they require the souvenirs to say Walt Disney World on them.... to make them more meaningful.
Encourage the kids to help you keep a running journal at night of what you've done to save for a scrapbook or just to refer back to. It's amazing how quickly you can forget all the funny things everyone does and says b/c SOOO much happens in such a compressed amount of time on a vacation.