Hi Tabitha!
Being "addicted" to Walt Disney World is a fairly common trait around here!
There's no real way to know what fantastic offer Disney will offer next or what resorts or time periods it may cover. What I always recommend is to book the Resort & Package you're comfortable with in terms of price & date. That way, if a special offer doesn't become available for your travel dates, you'll still enjoy the great vacation you had planned & budgeted for.
Then, keep an eye on the
Walt Disney World website's 'Special Offers' section often!
If a new offer comes out, call (407) 939-7675 & mention that you have an existing reso & would like to switch to the "such & such" offer. The Cast Member will advise you of availability under the offer & can even help you compare to determine what's best for you! The offer may vary by resort level in terms of which properties have availability, what % discount is available or what 'free' add-ons such as dining are being offered.
For example, I was once booked at Disney's Port Orleans French Quarter Resort (which is a great choice!) when a 'Buy 4 nights Get 3 nights Free' offer came out. I called in, but that particular offer was sold out at POFQ. We couldn't receive a discount off our existing package price at a moderate resort, HOWEVER we ended up being able to upgrade to a Deluxe Resort under the new offer & our total package price remained almost exactly the same! We were thrilled!
I hope you'll visit me again with any additional questions you may have.
Wishing you a very Magical time planning your next Walt Disney World vacation to celebrate your daughter's birthday Tabitha!
Kirsten