Hi Carbar
When I come across a situation like that I do two things firstly.
I don't know what sources you are using and whether this is at all possible but what I do is search using lots of different possible spellings for Magdalin - Magda, Magdaline, Madeline, etc and then search through Rotherfield records and note every other Lucke, Luck, Luke etc I can find.
It is possible that Edward could be a brother, have you checked out his marriage for any clues there?
Have you searched for any wills for any Lucks in the area at that time?
Kerry