“How much of Willie Brown’s DNA is in Kamala’s kids?”
She has no children. Those are Doug Emhoff’s kids from a prior marriage.
In fact, Kamala has only 4 living relatives in the United States: her father, her sister, and her sister’s two kids.
She has no other ancestry here since her father is from Jamaica and her mother was from India.
The woman has no connection to the Americans, no business ruling Americans, and if the immigration and naturalization laws had been properly applied, she probably wouldn’t even be considered a citizen.
According to an article written by Kamala Harris' father, he claims that Hamilton Brown was an ancestor of his, and was a slave owner in Jamaica in the 18th century.
Snopes, of course, says this is "unproven", but doesn't say it is false, which means it must be true.
https://www.snopes.com/fact-check/kamala-harris-ancestor-slaves/