Pauline, I have information about Catherine's background and the 1756 marriage to John Garrett, but I don't know whether the John Garrett she married was the Lezayre one you are looking for. Was his wife mentioned by name in one of his family wills?

Cath Tear married Stephen Radcliffe 1 Feb.1755 Andreas. They had one daughter, Mary, bapt. 4 Dec.1755 Lezayre. See http://www3.telus.net/lawson/twill/1756_027.html

She then married John Garrett of Andreas (not Lezayre - and there were several John Garretts in Andreas). "the s’d widow having of late intermarry’d with one John Garrett of KK Andrews..."
Their marriage has:
“John Garret of Andrews & Cathrine Radcliffe als Tear of Lezayre married Aug.1st” [1756]

Cath's will probably was: GARRETT, Catharine 1813 And E 2 0106415 (from Brian Lawson's website), but I haven't looked at this. The date coincides with her burial als Tear.

Are you working your way back from your own ancestor? Because if he/she was a Garrett from Andreas there is no evidence (that I have seen) that the John who married Cath Teare was born to a Lezayre family.

Sue