Requesting help to read date on Daly family headstone

[Maiden Stone]

  The headstone is in Saint Mary's Church Of Ireland graveyard in Streete, Westmeath.   https://www.buildingsofireland.ie/buildings-search/building/15400201/st-marys-church-of-ireland-church-barradrum-streete-westmeath

It says that local tradition suggests there was previously a Catholic church on the site.

[Maiden Stone]

In fact the internal evidence from this headstone is that this was a Catholic family - viz, the "IHS".

That was also my feeling It's a symbol popular with Latin-rite Catholics, although not exclusively used by them.
Any thoughts about the carving of a face in the top corner?

[Wexflyer]

In fact the internal evidence from this headstone is that this was a Catholic family - viz, the "IHS".

Any thoughts about the carving of a face in the top corner?

It is not meant to represent a face as such. Instead the face plus the wings and body below and engraving above are meant to represent an angel. Angels convey the souls of the faithful departed to heaven -  Luke 16:19-31. As an aside, angels have more than two wings, as can be seen on the stone.

[Wexflyer]

Scotland adopted the Gregorian calendar in 1600.

I don't think this is quite right. Scotland changed the start of the year (New Year's Day) to January 1st in 1600, but did not adopt the Gregorian calendar until 1752, like the rest of Britain.

[Maiden Stone]

Wexflyer, it's obvious that it's an angel now you've told me. 

Reply 12. You're correct. I was conflating 2 things.
https://www.nrscotland.gov.uk/research/record-guides/old-parish-registers/change-in-calendar

[Wexflyer]

At a guess - and it is much less certain than the angel on the right - the symbol on the top left of the headstone is meant to represent the tree of life.

[shanreagh]

As regards OP's comment that this headstone is in a Church of Ireland graveyard, I think I should point out that it does not at all follow that this is a CofI family. At the time the only graveyards were those of the established church so everyone was, perforce, buried in them. In fact the internal evidence from this headstone is that this was a Catholic family - viz, the "IHS".

Anglicans/Church of Ireland also use the IHS.  My gt Grandmother a CoI from the north (Co Derry)  has this on her gravestone in a NZ cemetery erected in 1888. In fact when I found it, the IHS was a pointer that it might be her stone plus the burial date obv.  The stone was erected by her husband a 'fierce Presbyterian' (quoting my mother) and I don't think he would be putting anything on that signalled a RC connection.  She also had lilies engraved
'Consider the lilies of the field, how they grow; they toil not, neither do they spin yet I say unto you, that even Solomon in all his glory was not arrayed like one of these.'

Looking at the info on the stone it says Mary Daly alias Fox so that will be a clue too. 

Above the saint/angel  there are fern frond-like 'things'.  I have seen this before.
Found that it symbolises    sincerity; humility; solitude

[Wexflyer]

As regards OP's comment that this headstone is in a Church of Ireland graveyard, I think I should point out that it does not at all follow that this is a CofI family. At the time the only graveyards were those of the established church so everyone was, perforce, buried in them. In fact the internal evidence from this headstone is that this was a Catholic family - viz, the "IHS".

Anglicans/Church of Ireland also use the IHS.  My gt Grandmother a CoI from the north (Co Derry)  has this on her gravestone in a NZ cemetery erected in 1888. In fact when I found it, the IHS was a pointer that it might be her stone plus the burial date obv.  The stone was erected by her husband a 'fierce Presbyterian' (quoting my mother) and I don't think he would be putting anything on that signalled a RC connection.  She also had lilies engraved
'Consider the lilies of the field, how they grow; they toil not, neither do they spin yet I say unto you, that even Solomon in all his glory was not arrayed like one of these.'

Looking at the info on the stone it says Mary Daly alias Fox so that will be a clue too. 

Above the saint/angel  there are fern frond-like 'things'.  I have seen this before.
Found that it symbolises    sincerity; humility; solitude

It may be straying, but while I have indeed seen the IHS monogram used in "high church" Anglican settings, I can't recall seeing IHS on a gravestone in a purely CofI cemetery in Ireland.  Which is not to say that it does not or cannot exist, but it must be rare - especially in the 1730s.
IHS is the central charge of the Jesuit arms, and was a leading symbol of the counter-reformation. It was very much a "Catholic" emblem in Ireland, which automatically meant that Protestants avoided its use. You can find academic papers supporting this assertion.
https://pure.qub.ac.uk/en/publications/the-ihs-monogram-as-a-symbol-of-catholic-resistance-in-17th-centu

The Lutheran church makes extensive use of IHS. Things may also be different in NZ, especially in such "modern" times as the 1880s.

[Maiden Stone]

IHS is the central charge of the Jesuit arms, and was a leading symbol of the counter-reformation.

With a sun behind IHS.