"In its first year, Harlequin put out a line of general fiction and educational materials, as well as a few romance tiles."
"[The publisher's wife, Mary Bonnycastle], along with Harlequin secretary Ruth Palmour, initially read the manuscripts. Palmour may have also illustrated some of the early covers."
The closest to "educational materials" that Harlequin published in its first couple of years was the two cookbooks (51 and 52) and the Knitter's Guide (71). Over the next ten years another seven tiltes might be considered educational.
Not mentioned is Jack Palmer, the founding editor of Harlequin, who made the editorial choices for the first number of years, not Mary Bonnycastle or Ruth Palmour. This is the first I've heard that Palmour may have done some of the covers. That's hard to believe as right from the start professional artists were used.
There are 10 Harlequin covers (two below) and, surprisingly, one White Circle.
Harlequin 235 - June 1953
Harlequin 407 - December 1957