Rosi
Only your SM can answer that question. WDW has been known to lower the room night minimiums for people who are local and have most of thier guests not planning on staying at the resort, but for the most part, they are pretty set. I was originally worried that I would not be able to meet my room nights and now am certain that I did not get enough, and I don't even know who all is coming to my wedding, but 15 of my 25 have already been booked up.
Also, keep in mind that if anyone has reservations using a different discount, DVC, etc., or in another hotel besides the 3 you chose (for instance, they want to stay at the GF tho that wasn't one of your resorts), those nights also count. You simply need to provide the ressie number to your SM/EM.
HTH