Interesting that you could read 'her brother' Thomas Long (who is probably her brother in law). On Ancestry I found the title of Cicely's will in 'UK Extracted Probate Records 1269-1975) that said:
1559 Coppinger, Copinger, Long formerly, Cicely, widow, St. Laurennce Jurie, London; Essex; Surrey 44 Chaynay
I was wondering whether the 'Long formerly' might mean that her maiden name might be Long (as well as her second married name). A Long shot...