Susan Clegg and her Friend Mrs. Lathrop, by Anne Warner
Little, Brown / A. L. Burt, 1904
In a relatively scarce occurrence, the Burt reprint of this title retains the Sacker design and her monogram (see below). Ridgwell Cullum's The Story of the Foss River Ranch is the only other title I have found like this.
One of two Warner titles that for which Sacker designed the cover.