Aruba is one place I would definitely recommend NOT doing an all-inclusive. I get why people do them at other islands but there are so many great restaurants to go to in Aruba and the island is safe and fun to explore. My co-worker went to the Divi for the all inclusive with her 10 year old earlier in the summer and said it was great.
With that said - Aruba is kid friendly. My oldest turned 20 this week and we have been going there since before he was born. My kids love going there - but they are beach, pool , reading type of kids - they don't need a lot of entertaining. Snorkeling is fun - we bring our own gear and drive just north of the high rise area and snorkel at Boca Catalina - it is one of the stops that most trips stop at anyway. I have heard nothing but great things about Aruba Bob but haven't tried him yet.
In addition to the water sports mentioned highly recommend Great Mabel ---- basically a giant inflatable lounge chair like float that holds 2 or 3 people and gets towed behind the boat - lt leaves from the pier by Riu I believe. It is much better than a banana boat ride and jet skiing (IMO) and not expensive. The 1st time we tried my daughter said that she had never heard me laugh like that! Not sure if that is included in your all-inclusive package.
Explore the island either on a tour or on your own. head out to the Caves and grab lunch or a drink at Boca Prins. Head out to the lighthouse/gold mine/fort/natural bridge area and roam around - it is a unique place. Baby Beach is popular but getting more touristy. DePalm Island is an all-inclusive water park type place with probably the best snorkeling I have seen on the island but it is a little over priced. I am sure the Divi will have numerous activities during the day. Sounds like you have a bunch of kids going - if they get along they will all entertain each other also.
Not sure how many restaurants you plan on hitting outside of the Divi. If you need advice on restaurants let me know.
this link has a ton of info about Aruba.
http://www.ArubaKid.com