The gates - Jennifer Johnston

Once, the villagers would tip their hats respectfully when the McMahons drove out through the ornate iron gates at the end of the drive. But that was back in the days when the Major's family were prosperous. Now the estate is slipping into peaceful decay - and so, it seems, is the Major, its last occupant.
Then Minnie, the Major's rebellious niece, returns home. She disrupts his tranquillity, forming surprising friendships with the feckless Kelly family. For together, Minnie and Kevin Kelly have hatched a plan to raise badly needed money - a plan which involves the gates themselves...