Hi Tanya,
You will love staying at Disney's Grand Floridian Resort & Spa. The Victorian style architecture is amazing, and you will truly feel like you are walking back in time. Located right on the Monorail is definitely a plus especially with small children. You will not need to break down your stroller to travel on this and not wake up your little ones.
There is one rocking chair available at the Grand Floridian. When you make reservations, you will need to request this, or you can call the resort at (407) 824-3000 and request it for your entire stay. I know how important it is to rock your babies to sleep as well, and I appreciate your question. It is a great one!
I want you to know that there are also
Baby Care Centers located at all of the theme and water parks. These have rocking chairs and quiet areas as well to feed or change your children. They even have Carnation Formula at no additional charge for you. I used these areas often.
Please send me a follow up question if I can help you further, Tanya. Have a magical vacation!