The BBC report the passing of Lady Mairi:-
http://news.bbc.co.uk/1/hi/northern_ireland/8365816.stm
County Down is renowned for its coastal beauty and rich heritage and
tucked away along the shores of Strangford Lough is Mount Stewart
Stately home - a National Trust property which combines these two
qualities in one grand estate. The estate which boasts celebrated
gardens and is one of Northern Ireland's most popular National Trust
properties was the home of the Londonderry family of Newtownards. The
family link is ever present, as Lady Mairi Bury, whose father was the
7th Marquess of Londonderry, still lives at Mount Stewart. During a
rare recent interview Lady Mairi talked about what it was like growing
up surrounded by world famous visitors, in an idyllic corner of County
Down.
http://www.culturenorthernireland.org/article.aspx?art_id=1229