On 10 February 1841 she was married at Castle Ashby to John Hume Cust, Viscount Alford, elder son of John Cust, 1st Earl Brownlow, and the heir to a portion of the large estates of Francis Egerton, third and last Duke of Bridgewater.
In 1849, this property passed to Lord Alford, but he died in 1851, leaving his widow with two sons.
Lady Marian Alford was an accomplished artist, inheriting her tastes from both her parents.
She did not receive any regular education in art, but her drawings and paintings attained a high standard.
[4] She was an editor of The Handbook of Embroidery which was the school's first guidebook put together by Letitia "Lily" Higgin.