Dear Jane,
There isn't any absolute way to be sure that these two children are those of
David and wife. How many other Davids were there in Llanuwchllyn at the
time? I doubt it was that unusual a name. Some are lucky to have Isaacs,
Ishmaels, Samuels and Solomons (all coming from the great religious revival
by the way), but those of us with Johns, Davids, Richards and Williams must
just record and say "possibly". That is, unless a tombstone exists or some
record in a vestry book of a charitable donation to a family... and not all
parishes have vestry books remaining
The problem with your two examples is that, as you realise, they could just
as well be adults. Here, looking at the format of the rest of the register
is useful. Sometimes clues are given in that adults might be more often
followed by a description such as of occupation or abode whereas children
might not be however this is not a hard and fast rule and depends very much
on who was keeping the records.
Cross check with Bishops Transcripts as well because sometimes three-name
patronymics might be given ie Catherine David could be the same as Catherine
David Thomas. Or, in the BT, which might have been the "fair copy" or the
"rough draft" for the PR, additional info of other sorts might be given.
It is interesting to note the names that families wanted to continue. One
of my gt gt gt grandparents had no fewer than 4 Johns and 3 Janes. A bit
like your possible Catherine.
Hope that gives some useful ideas anyway.
Yours,
Ian,
London SW9