I am a resident of New York. My divorce however was handled by a Florida court. At the time of my divorce my income was less than it is now. My ex is threatening to take me back to court and sue for increased child support payments. What is the law relavant to this? Is this different then a standard cost of living increase? (What is the percentage for COLA in NY?)

How much did your income increase? Of course she can ask for one... whether she gets it will depend on how much more you are making. Child support is income based so obviously if your income changes by a great deal then the support should too. Each state has their own amount that they say is substantial to warrant a modification. It ranges from 12 (I'm pretty sure that's the low end) up to about 18% increase or decrease to warrant a change in support.