Hi Michelle...we've gone on trips with extended family 5 times now. We've pretty much had all our rooms together with the exception of 2 trips, and even then we were in same building just maybe few rooms away. Rooms booked directly by each party either on their own or thru our TA.
Disney reservation system can set up a "travel with number" or "travel plan number" upon request and each person who reserves needs to request their individual resort reservation number be listed under the travel plan number. This will hopefully increase your chances of being placed closed together. The travel plan number can also accommodates notes for requests such as a specific resort location-just remember its only a request, but I believe room assignors will try their best to honor them . Good luck!