Why did Harriett Wombwell sell her Irish lands?

Strangford Lough. The lands of Ballyedock, owned by Harriett Wombwell were somewhere along this stretch of coastline.

The 1881 auction in Belfast sold off the lands in ten lots, with each lot divided into different parcels. Harriett Wombwell would have been in possession of a very reasonable income indeed, given regular rental payments. So why instruct those lands to be sold off?

Presumably because dividing the rentals into 10 parts between 8 children and 2 grandchildren, would have been complex and costly. For them to then manage the lands as absentee landlords through representatives across the water, even more unrealistic. 

And furthermore, well, Ireland was Ireland, volatile, unpredictable and permanently problematic. The politics of the day can have provided no encouragement to the landed absentee class. Fenian violence through the nineteenth century, and the formation of pressure groups like the Irish Land League had impelled the British government to seek to pacify the ever-troublesome Irish by introducing a series of land acts providing better protection, security, and reduced rentals for land tenants. 

Indeed, it was in exactly 1881 that the Second Irish Land Act was passed, enshrining a principle of dual ownership by landlord and tenant and enhanced rights for compensation and improvement.
In such a climate for a suburban London family to cling on to its Irish lands can have made little or no sense at all. Simply a case of more trouble than it was worth for diminishing incomes.

There is no evidence that Harriett herself had ever been to Ireland, and it can almost be taken for granted that when the auction took place, none of her children or grandchildren would have been in attendance.