Although not a big fan or her politics, I would think Elizabeth Hanford Dole would offer an attractive naming option.
Liz Dole is a 1958 Duke grad and has remained very close to Duke over the years -- serving on the Board of Trustees and as chairman of the Alumni Association.
After that, Nan Keohane pops to mind -- several dorms are named for ex-University Presidents. She wasn't my favorite either, but at least she was better than Doug Knight.