looking for a particular regency romance in which the heroine has been scarred by carriage accident?

sometime in the late 70's early 80's my sister and i both read a romance novel in which the main characters whose names i believe were Edmund and Katherine married. Edmund was a widower, and Katherine a poor girl who had been in a terrible carriage accident which caused her to become disfigured on one side of her face. he didn't know what she looked liked prior to the wedding, that she was scarred, but after the initial shocking discovery and a host of other events which threatened their happiness they fell in love and lived happily ever after. first person to give me the correct title gets the 10 points. have been looking for this novel for over 20 years so your help would be invaluable and greatly appreciated