Mary Tandy is recorded as one of the principal lessors in the parishes of Clonrush and Inishcaltra, barony of Leitrim, county Galway at the time of Griffith's Valuation. She also held three townlands in the parish of Inishcaltra, barony of Tulla Upper, county Clare.The Tandy family, including the United Irish leader, Napper Tandy, were associated with this estate in Mountshannon from the 18th century. In the 1870s Mary Tandy held over 4500 acres in county Galway and 404 acres in county Clare. The property later became associated with the George and Wakely families, family connections of the Tandys. It was sold to the Congested Districts' Board in 1915.