In the early years of the 18th century, post 1705, Margaret Vaughan inherited Llanelly House from one of her elder sisters on her death in 1706/7. In 1691 Margaret had already married Sir Thomas Stepney (5th Baronet), thus the Stepney lineage at the house had begun. Thomas Stepney was most likely responsible for the commissioning of the new house's front façade with its present third floor with hipped roof in a Queen Anne style, work that probably was not fully completed until 1714, as is evident from a date on one of the surviving lead drainage hoppers.