Dame Beatrix Margaret Lyall (née Rostron, known as Pile 1899-1914) (27 October 1873 - 8 May 1948) was a social reformer and local politician.
The daughter of Simpson Rostron and Christina Jane née Riley. On 15 June 1899 she married George Henry Hudson Pile who changed his name to (mother’s maiden name) Lyall 1914.
Involved in Mother’s Union (becoming Vice President), and Primrose League
First woman to be vice Chairman London County Council 1932 – 1933
Elected March 1919 for Fulham East as Municipal Reform Party., lost seat 1934 election, won by-election same year, but did not stand 1937. Served in various government departments WWI, and on several LCC committees.
Article in Who’s Who
Wikipedia page