Those are JK wheels. You would need JK to TJ wheel adapters to run those. Plus, those calculate out to about 28". Should be fine, but still smaller than the 31's you have now.
Your kid's TJ has a 5X4.5 bolt pattern. You would need to get adapters to run these wheels. It's fairly common, someone even wrote up a how-to on here: JK or JL wheels on a TJ