hi! I have two girls the same ages!
I take my girls to Ocean In Motion all the time(it's $150 for the year for 2 kids, but well worth it... especially with the winter coming up).
I also have a membership to the Philadelphia Zoo... you can get a pass for your whole family for the entire year for $100, and includes free parking (saves you $10 each trip).
there's also a cool place in Bordentown called Animal Kingdom where you can feed giraffes! It's free for under 3 years old. http://www.animalkingdomnj.net/
During the summer there is Sesame Place.
other than that, I guess I take my girls to the park alot. If you are bored with Freedom Park, there are lots of other parks in the area. Every park I go to makes me love the one by my house even more.... Longbridge Park, right off of Rt 541 (Mt Holly By-pass)in Hainesport. the playground equipment is perfect for these ages, and there are all sorts of walking trails in the woods to run off some excess energy! :-D