The monetary amount is a red herring. In most US jurisdictions, at least, child support is factored as a percentage of the paying parent’s income. Sure, $46,000/month seems like a HUGE amount to us non-celebrities whose income may required multiple months—perhaps years—to earn, but to a billionaire, that may very well be far less than the 17% of income that NY, for instance, requires parents to pay.
So, sure, we can’t imagine receiving that sort of income, but I doubt many people would be up in arms about him having to pay $650 a month if his income were only $46k per year (which is pretty close to the median income for American households), even though that is actually a lot of money for some people.
Child custody and support battles are fraught with accusations, many which border on complete untruths. I doubt anyone knows the real reason why she needs a 24-hour nanny, but her schedule likely plays a huge role in this. Sure, waiting four years to make claims on paternity seems strange, and to the outsider may look like she’s trying to cash in on what his daughter with Selma Hyack is getting, but we can only make assumptions about that.