Sher,
Mulladry and Shewis are both in the parish of Kilmore. They are townlands rather than names of specific farms. Mulladry is 748 acres and Shewis 214. They are several miles apart.
In the 1901 census, Mulladry had 40 houses and a population of 180; Shewis had 8 houses and a population of 36. See:
http://www.census.nationalarchives.ie/pages/1901/Armagh/Richhill/Mullad…
http://www.census.nationalarchives.ie/pages/1901/Armagh/Richhill/Shewis/
No Blairs in either by 1901.
I looked in the tithes for 1833 and there are no Blairs listed in the parish (Kilmore) then. That, plus linen weaving, points to them being labourers. The general arrangement with labourers in Ulster was that they rented from a local farmer, usually on an “at will” basis, ie neither party needed to give notice to quit, which left them free to move at short notice should better work be available somewhere else. They could pay their rent in cash but they often paid it by an agreed number of days work on the farm each year, after which they were free to take any other work that might come up eg on another farm or on government schemes such as road building.
In rural areas most weaving was done at home using hand loom weaving machines, such as are still used in the Outer Hebrides in Scotland to make Harris Tweed. These machines were collapsible, so as to be stored out of the way when not needed and for ease of transport should the weaver move home, as they often did, to follow the available work.
Most weavers in Ulster were labourers who earned a bit of extra money by weaving in the winter months when there wasn’t much labouring work required on farms. This meant that labourers in Ulster had a slightly better standard of living than elsewhere in Ireland. It also gave them some ready cash (in a society that mostly operated by barter) for the things that could not be bought by barter, eg a ticket to America.
They are unlikely to have been making linen directly for the Richardsons, though it’s possible they did. In most areas, the weavers were self–employed and sold their linen to commercial buyers at the local market (possibly in Richhill in this case).
At one time weavers wove a lot of cotton but the interruption of supplies from the southern US states during the American War of Independence in the 1770s meant they focused on other materials, notably flax (which linen is made from) and which grows well in Ireland in contrast to cotton which won’t grow at all. They did weave other products eg calico and wool as required, but by the 1800s it was mainly linen.
As the 19th century progressed, water powered linen mills were introduced all over Ulster. These were faster than home weavers and often made better quality material and so gradually made the home weaver redundant. In addition, the factories also mostly employed women and children (being nimbler and cheaper) so this impacted on male employment too. At a time when farms were starting mechanise and so needed fewer labourers, the average labourer/weaver therefore faced a bleak future and so these combined changes were a major factor in many a labourer’s decision to leave Ireland during the 1800s.
A little more information on this link: https://www.irish-genealogy-toolkit.com/flax-plant.html
If your ancestors were Quakers then there are quite good records going back to the 1700s as you possibly know. Findmypast has a lot of Quaker records for Ireland and there are copies of the Ulster Meeting House records, including Richhill, in PRONI in Belfast. In the 1700s and 1800s Quakers in Ireland rarely if ever had gravestones (it was seen as pretentious or ostentatious).
Kilmore Church of Ireland parish has 5 churches. The Diamond, Kilmore, Mullavilly, Richhill and St Saviour’s. Sadly Richhill lost all its early records in the 1922 fire in Dublin and now has no baptisms before 1878 and no marriages before 1845. So if that’s where the Blairs were baptised or married, the records probably don’t exist. The records for the other 4 churches are in PRONI in Belfast.