There is no reality in which she had a 50% stake in hinge at the time of sale. I would be shocked if she had >1%. She was involved only in the very early stages.
True, though the stock market has gone up a ton since 2018. If she put $50M into a mix of tech stocks, crypto, and Bay Area real estate in 2018, she could have hundreds of millions by now. I agree she likely doesn't have a billion if the Hinge sale is the primary source of her wealth.
Hinge is worth $2 billion today (according to some random site, would love a good source) and was fully acquired nearly 3 years ago. And there's no chance she had 50% equity. It's not even clear if she had any.