This website dedicated to info on celebrities says the following:

What “private businesses” are these? A reader raised the question of her finances with us a few months ago when her reported net worth figure was $US 10 million, $15 million less than what it is now. We were dubious, but websites which have a reputation to maintain are unlikely to make wild assumptions. There are people who dedicate themselves to ferreting these sorts of facts out.

What we do know is that she keeps company with some very wealthy people, including Bill Gates, the Clintons, Google and Facebook execs, and of course she has given a lot of commercial purchases (paid for by the Taxpayers) to Pfizer, the top dogs in which are new billionaires. Hmm.

Dear Leader with super-rich friends in New York in 2019.