Below is my intended solution.
American First Ladies (by first name)
Martha Jefferson Randolph,
Angelica Van Buren,
Mary Harrison KcKee,
Bonus questions: Which first lady served under two presidents?
However as pointed out by Guest and eluded to by Charlie, it would be more aptly titled Hostess of the White House. You can see my Reply to Guest for more details, (in case you want more information on American First Ladies then you ever really wanted to know.)