Hi Cathy,
I am excited to hear about your kids' first trip to Walt Disney World. They are going to have the time of their lives. I hope you ready for some fun! My daughter is also nine, so I am glad you came to the Disney Parks Moms Panel, as I have a few awesome suggestions that might be right up your twins' alley.
In regards to the pool hours at Disney's Port Orleans Resort - Riverside (my favorite moderate resort, by the way), they can vary and change with the seasons or weather, so your best bet would be to check with guest services upon arrival to the resort.
Over at the newly re-imagined Disney Springs, there is so much to do and see that I can't fit it all in my answer. However, here are some of the highlights that I think your twins would enjoy. If they have an adventuresome personality and do not mind heights, you must go to
Characters in Flight, Operated by Aerophile. This tethered balloon takes you up to soaring heights to get amazing panoramic views of Disney Springs, as well as the nearby theme parks. It is first-come, first-served and is located in the West Side area across from Starbucks. Also in the West Side area is
Splitsville Luxury Lanes, where you can bowl and dine on some delicious food. This is not your average bowling alley food. There is world-class shopping of some of the hottest brands, such as Lucky Brand, UNDER ARMOUR, UGG, and francesca's. You will also find The LEGO Store and World of Disney.
Goofy's Candy Co. is located in the Marketplace area and would delight anyone with a sweet tooth.
I hope your trip is full of magical memories.
~Allison L