Hello Frances,
I have looked at my latest MNB CD (Xmas) and the only mention of William Garret - in 1794 - is this.
NSS Oct 1794 25 Wm Garrett - Pat Caley
NSS Oct 1794 26 Wm Garrett - John Caley
NSS Oct 1794 27 Wm Garrett - John Quan
An extract from his Will.
1794 - William Garrett of the parish of Lezayre having departed this life on or about the 9th. Day of October last past
intestate,
I also checked your MNB CD for Joney Garret als Christian in 1819 - and there is no mention of her.
The Christchurch FHC is still not open yet, so I can't access any films of the Lib Vastar 1790 - 1800.
Averil