Margaret Wyatt was ch. 1752 to William Wyatt and Susan Langston so puts her age at marriage to about 21.

If there is nothing helpful in the parish entries you could speculate that Robert was of similar age and work out from that point e.g

1. Robert ch. 1747 to William Quayle and Ann Fargher ( he may have changed his name to Quayle later)

2. Robert ch. 1748 to Thomas Fargher and Ann Quirk ( my favourite )

3. Robert ch.1749 to Edward Fargher and Jane Quine

4. Robert ch. 1752 to William Fargher and Margaret Callow

The last two may have married on the Island.

Len Faragher