Hi Heather
You can search all the BMDs free on
www.ancestry.co.uk Choose the complete version - the link is on the first page if you scroll down on the right hand side. Do you know Daisy's mother's maiden name? If so, you can look through the births and find one with the right maiden name against it and then you will at least know when and where she was born. Remember that Daisy may be a pet name - she might be Margaret for instance.
If you are not sure if she married then looking for her death is going to be much more difficult.
You could try writing to the cemeteries in Skegness or to the local register office but it really will be needle in haystack time. How old was your uncle when he went to the grave? That gives a cut off time.
You could look for possible marriages on ancestry too. Is anyone in the family likely to have left wills that might mention her? A long task ahead I'm afraid.
Andrea