There’s a birth for a Bridget Mullan on 6th June 1887 to James Mullan and mother Mary Anne Mullan (not McNamee). The birth was in the townland of Killygonland. James was a farmer there.
https://civilrecords.irishgenealogy.ie/churchrecords/images/birth_returns/births_1887/02564/1948146.pdf
A sibling Mary Ann in 1885:
https://civilrecords.irishgenealogy.ie/churchrecords/images/birth_returns/births_1885/02651/1977350.pdf
Another in 1892:
https://civilrecords.irishgenealogy.ie/churchrecords/images/birth_retur…
The Valuation revision records show them staying there till 1900 when, judging by the 1901 census, they had moved to Strews:
http://www.census.nationalarchives.ie/pages/1901/Tyrone/The_Sandholes/Strews/1730047/
Same family in 1911. Note that they had been married 35 years and had had 10 children of whom 7 were still alive at that time:
http://www.census.nationalarchives.ie/pages/1911/Tyrone/The_Sandholes/Strews/859754/
Can’t see a marriage for the couple in the civil records.
The Valuation revision records (PRONI website) show James on plot 4 in that townland, an 11 acre farm. He looks to have bought the freehold in 1908 under the Land Act (which allowed tenants to buy with a Government mortgage). The owners name changes to Mary Anne in 1922 and then to James in 1928.
Mary Anne’s will is in PRONI in Belfast. (Not on-line. Visit required to view). Abstract here:
Mullan Mary Ann of Strews county Tyrone widow died 17 September 1926 Probate Londonderry 26 November to Daniel Higgins farmer and Michael McGurk merchant. Effects £141 8s.
The farm in Strews today is on the modern Strews Road. Looking at a satellite image, it looks to still be farmland. The old buildings look to have been demolished and there’s a fairly new house there today. (Sadly Ireland’s not an open air museum and older buildings often get replaced). You can see the property today using the Griffiths maps, and the satellite option. It is 4 or 5 miles outside Cookstown (to the west).:
https://www.askaboutireland.ie/griffith-valuation/index.xml?action=nameSearch
The Mid Ulster Mail of 28th October 1972 reports the funeral of 2 IRA men, one of whom was John Patrick Mullan of Strews. The two men had been shot dead by the army at Ardboe the previous week. Can’t say if John Patrick was part of your family but it’s obviously a possibility. The article criticised the fact the IRA gave the 2 men military style funerals and the authorities had not intervened.
The newspapers contain numerous adverts in the 1970s and 1980s indicating Frank Mullan was farming in Strews and had various agricultural products for sale (hay, heifers, pigs, vehicles etc). Can’t see anything later than about 1990, so can't say whether they might still be living there. You could knock on the door and enquire.