I just discovered yesterday that my Great Grandmother was called Elizabeth Lesage. She was married twice, first time to somebody called Kerney or Kenny. Second marriage was to my Great Grandfather, Joshua Soper. Only child I'm aware of at the moment is my Grandmother, Mary Soper - DOB12/8/1894. At the time of my Grandmothers birth they were living in Bethnal Green, London. I've found several Lesage's in that area on the IGI but have not established any connections yet.
Does any of this tie into what you have? I'll keep a look out for your Matthew John as I check these out.