Hi Libby
Yes, there are many different Smith lines in the East Sussex area and I have done some work on sorting them out. So far I have about 6 major lines and 6 minor ones.
Yes it is the right couple; see below, I do not know why it did not turn up in my first search;
S.M.I. Place: Ashburnham, East Sussex, Date: 13 Mar 1745/6:
Subject: John MEPHAM, Mr. Ninfield ( meaning he is from Ninfield )
Spouse: Jane SMITH, Mrs. Battle ( meaning she is from Battle.)
This is where it becomes interesting for me, and is based more on circumstantial evidence then hard facts. From all the deductions using the SMI and other resources, it would appear that my ancestor Richard Smith ( 1705-1787) was a younger son of Thomas who died in 1739 ( innkeeper of the George ). He is not named in the will of Thomas, but a Charles and a Thomas whom he leaves the Inn to. Your Jane was the youngest of this family, born 1709 in Battle.
At least this is how I see it with the sources available now.