i second spockey's wooloomooloo!! more stroller friendly than some of the other places too. sala thai downstairs is also good if you fancy thai. i've heard Finds upstairs on the roof is nice but not sure how kid friendly they are up there.
elements is an expensive mall period... wooloomooloo is just as $$$ as the ones on the roof. i'm sure the chinese places are cheaper but haven't tried any of them yet.
Hi there. Can't remember the name of the place but on the roof there is a cafe type place that does salads etc. Nowhere near as pricey as the restaurants. If the kids are older and active the restaurant looks out onto the big open plaza that they can run on.
Another option, if you are prepared to be a bit more casual, is grabbing a burger from Three Sixty (best burgers and fries in town!) and eating them on the terraced seats over looking the ice-skating rink.
I really like the Chinese restaurant 'Xia Mian Guan' opposite 360 and 'Wang Jia Sha' beside Fortress. Both are good value and have plenty of high chairs/baby seats, tasty food and fast service. FINDS upstairs is nice too - (my son is always given free juice when ever we go there)
A friend recommended Nahm (Vietnamese/ Thai food) opposite Zara but I havent tried it yet.