Another Non Series #115 Preparation for Motherhood by Elizabeth Scovil has been found.
This one is a bit newer than the one I had already- but it is still pre-1900. The differences between the books are that the newer one has a flatter spine while the older one has a rounded spine contour. Also the older one has an exaggerated weave of cloth on the cover compared to the newer one.

Here they are:

Older

Newer