She succeeded to the Lainshaw estate following the death of her older brother James in 1767.
Elizabeth married firstly Alexander Montgomerie-Cuninghame of Kirktonholme (d. 1770?) and secondly John Beaumont.
- 1David was the son of Jean Montgomerie and Alexander Laing, Rector of Donaghadee. He inherited Lainshaw from his uncle James Montgomerie who died ca. 1726 without issue.