Hi Anna,
My Great-Grandmother was Lucy Jane Alley of Kings End, Bicester. I have traced her family back to the C16th, but not on the Alley side all the way. Where did you find your leads?
In terms of the Leveret alias, I found this useful article online through a Google search and hope it's useful for your research:
'....Often the names continued in this way for many generations. An example
is ALLEY alias LEVERETT around the Otmoor villages, which is recorded from
the early 16th century to the late 18th century at least. The reasons may
have lain in the system of copyhold land, for example when a mother with
children by her first marriage remarried, the children would often take the
surname of the stepfather but retain the old surname as well to prove their
right to the copyhold land. This was probably because the only place where
the entitlement to copyhold land could be registered was in the manor
courts and as birth certificates did not exist, it was far easier to use
both names than provide witnesses to make declarations or go through other
more complicated procedures to establish their rights. early surnames were
often simply not fixed. One man adopted one name, maybe from his father, or
his location, or his occupation, while his brother adopted another, from
his different occupation, his physical appearance etc - and the name
persisted. For instance, the family of Mrs Will Shakespeare dithered
between Hathaway (location) or Gardener (occupation). The Alleys were
pretty well to do (both sides of the county border) and one or another of
them might have been either fast on his feet or rather timid (Leverett =
young hare) Quite a number of alias names can be explained in this way -
and where a surname was common, there was a tendency to qualify it (Groom
alias Buff, Groom alias Townend)'
(from
http://archiver.rootsweb.ancestry.com/th/read/OXFORDSHIRE/2005-04/1113050264)