 Trelawny was involved in a lawsuit with his step-mother over his estate, which was resolved in 1716 to the relief of his financial problems.In May 1716, the bishop consented to the marriage between his daughter and nephew which took place on 17 July 1716.In 1756, at the age of 68, he succeeded his cousin Sir John Trelawny, 4th Baronet in the baronetcy.