That combination of functions, milling grain and processing textile at the same site, was not uncommon in medieval and early modern Ireland, where a single reliable water source might be put to several uses by the same landowning family.

The Nugent family appear to have controlled the mills at Gilbertstown for some time. A reference from 1647, drawn from the Calendar of State Papers Ireland, records that a fine of 9 shillings and 4 pence was levied on Thomas Nugent for two mills at Gilbertstown, as part of a broader assessment of £15 raised across a group of Westmeath mills to pay Captain Ignatius Nugent of the Irish Confederate Army. The Irish Confederate Army was the military force of the Catholic Confederation of Kilkenny, the alliance of Irish Catholic landowners and clergy that governed much of Ireland during the 1640s conflict. The levy suggests the mills were operational at that point and of sufficient value to be worth taxing. Whether the medieval mills that had earlier been associated with the Nugent family occupied precisely the same ground is uncertain, though they are thought to have been in the same general area as the corn and tuck mill later marked on the first Ordnance Survey six-inch map of 1837.