Surrounding the Burisma Holdings story is a myriad of fake news and misinformation, you can’t believe everything that you see just because a trusted source posted it. Sometimes people get the story wrong which is why it is important to correct the record when it happens.
There is a meme going around stating that Nancy Pelosi, Joe Biden, Mitt Romney, and John Kerry all have children who work for Ukranian oil companies. There is no evidence to suggest this outside of Hunter Biden, the information for the other three is scant and unreliable.
It is possible that the original creator of this meme got mixed up with Biden’s ordeal in China where similar circumstances apply. In that case, John Kerry’s son worked with Hunter Biden at an investment firm that got millions from China’s central bank.