My first guess: Amy Klobuchar. My second guess: Kamala Harris.
Biden promises he'll pick a woman as his running mate
Yahoo News, Mar 15 2020 9:48 PM
Joe Biden has promised he would select a woman as his running mate if he wins the Democratic presidential nomination. "I commit that I will in fact pick a woman to be Vice President," Biden said during the Democratic Presidential debate. "There are a number of women who are qualified to be President tomorrow. I would pick a woman to be my Vice President."
https://www.aol.com/article/news/202...mate/23951261/