After World War II
, unhappy with the thankless and repetitive task of changing her daughter's cloth diapers, along with the mess the soiled diaper made to the surrounding bedsheets and her daughter's clothing, she came up with a possible solution. With the use of a sewing machine and a shower curtain, she succeeded in developing what is considered the first waterproof diaper cover.
Not only did this new diaper keep the bed and clothing from becoming wet or soiled, but it also did not cause chafing
or diaper rash
Donovan was granted four patents
for her diaper cover, including the use of plastic snaps as opposed to safety pins.
In 1949, she attempted to sell what she called the "boater" to a number of different manufacturers; the effort was, at first, largely unsuccessful. She later started selling the waterproof diaper at Saks Fifth Avenue
Two years later her company and patents were sold for $1,000,000 to the Keko Corporation.
Donovan was granted 20 patents from 1951 to 1996. These included woman-related essentials and other convenience items, such as a facial tissue box, storage container box, towel dispenser, hosiery clamp, envelope and writing sheet combination, closet organizer, and dental flossing products.
In 1985, she invented the product DentaLoop, a two-ply dental floss that eliminated the need to wrap the dental floss around one's finger for use.