I started with governors. Every female Democrat governor currently in office is white. Most are old.
Senators. Every female Democrat US Senator is white. Most are old.
Democrat Cabinet members, former. Well, there's Alexis Herman, Clinton's second Secretary of Labor. She's not white, but she's old (62). Hazel R. O'Leary, his Energy secretary, is African-American, but she's 72. The rest of Bill's female cabinet members are white and ancient.
And that's as deep as I am going to dig. I suppose there may be someone in Congress who meets the three-rule criteria, but I'll leave that to others to dig through. McCain has more choices - Secretary of State Condoleezza Rice, Secretary of Labor Elaine Chao are both young-ish and non-white.