Hi Muggins, I'm only too happy to help!
I'll put what information I have here;
There was John Lishmund (1777 - 1843) and Jane Giles (1781 - 1844), both died in Plymouth.
John was recorded as being from Oxford Rd, Plymouth and was buried 10th September, at Charles the Martyr church, Plymouth.
Their children were Edmund Lishmund (1808), John Giles Lishmund (1808) and 'unknown' Lishmund (1808), Mary Lishmund (1810 - my 3rd great grandmother), Jane Giles Lishmund (1811 - 1851), Edward Frost Lishmund (Charles' father 1813 - 1883), Elizabeth Giles Lishmund (1815) and Tasmin or Tamsin Lishmund (1819).
There are a few other possibilities for other siblings, but I shall contact this relative in Saskatchewan and get his valued opinion.
As of yet, finding John and Jane's parents have proven extremely difficult, but I hold out hope!