What did Francis Crick and James Watson discover that Rosalind Franklin didn't?
There were staff migrations and personality issues, information leaks between researchers and other factors. Her boss annoyed her. Watson and Crick used her geometry of a helix with previously known DNA nucleotides and phosphate from other researchers. She actually had discovered and photographed the helices. 

Franklin had obtained the basic structure, shape and measurements of DNA. 

Franklin:

She used careful hydration from 75-90% in order to obtain her best pictures. Hydration makes the DNA expand into a visible helical configuration. She used cylindrical Patterson map calculations to determing DNA's density, unit cell size and water content. From this she deduced the basic dimensions of DNA strands, and that the phosphates were on the outside of what was probably a helical structure. Her research was briefed/presented in an internal meeting/seminar at the college and was published officially in 1953 in support of Watson and Crick's presentation.

Watson and Crick:

Watson and Crick suggested a basic framework of a helical molecule for DNA,  Without elaborating precisely. Watson and Crick combine all the findings of other scientists, for the bases and acids of DNA, with Franklin's helix into a synopsis into a correct helical molecular structure. The phosphate and CAGT were already known, and they arranged it into a helix.
Judge for yourself if their research was brilliant research, if it is a discovery, or if it is laying the last pieces of a puzzle assembled by other researchers. 

Watson and Crick stayed friends with Franklin after 1954 and shared friendly correspondence and some road trips, and helped with her health issue.

full pdf at .edu source here



If you check that publication, what may seem dishonest is that they iamge a photo by Franklin in support of their work, but only as a blurred photo, when they actually had access to all of her best photos. I haven't been able to find if Franklin published her photos independently in Nature or another magazine.



It was obviously not her best work. 

Franklin obtained undenatured DNA gel from a Swiss researcher at Berne university, Rudolf Signer. 

She used careful hydration from 75-90% in order to obtain her best pictures. Hydration makes the DNA expand into a visible helical configuration. She used cylindrical Patterson map calculations to determing DNA's density, unit cell size and water content. From this she deduced the basic dimensions of DNA strands, and that the phosphates were on the outside of what was probably a helical structure. 
Her research was briefed/presented in an internal meeting/seminar at the college and was published officially in 1953 in support of Watson and Crick's presentation. 



The Nobel Prize in Physiology or Medicine was awarded to Watson, Crick and Wilkins in 1962. The prize was not awarded to Franklin; she had died in 1958, and although there was not yet a rule against posthumous awards, the Nobel Committee generally does not make posthumous nominations. Watson suggested that she should have won the nobel prize for chemistry in his book, and Franklin is known through his distorting lenses. Ideally it would be interesting to know what Franklins personal letters and documents told of her research. Perhaps there is an autobiography of franklin? if not there should be one! She had differences with the lab director, professional or personal, we don't know, so she changed labs after only 2 years, leaving Watson and Creek and the research at King's. In july 25,2020 it will be the centenarian of her birth... She is older than Watson and Crick and would be 99 today. Perhaps she was not fond of helices?