There are many deaths recorded fort Florence Burton, so it might be a good idea to find out when she was born.
If you can track the marriage certificate it should give her father's name and occupation. With this it should be possible to find her on the 1901 and/or 1911 census returns. The census returns will give an age and place of birth, also her mother's first name to help track your great-grandparents' marriage. With a name, year and place of birth you can find her birth certificate to get her precise date of birth. Once you have a birth date you can check BMD records to eliminate the red herrings and find Florence's date and place of death.
When you find the date and place of death it should be possible to search burial records or local newspaper reports The death certificate should tell you if the death was recorded by a coroner - if so, the inquest records may lead to an undertaker.
Keep using this thread to post the step-by-step results of your search and friendly Rootschatters will help you move the search forward.
Good hunting!
Philip