steepholm

Very doubtfully, I'd say. Not that Jourdain was particularly rich, but she was a pretty eminent person in her field, that of furniture history and design. From DNB:

It was her knowledgeable and authoritative contributions that helped transform Country Life from a relatively lightweight, romantic magazine into what Walter Runciman called 'the keeper of the architectural conscience of the nation' (Spurling, Secrets of a Woman's Heart, 90). She spearheaded a shift in taste away from Victorian ostentation, fussiness, and clutter to an earlier simplicity and severity. In Furniture in England from 1660 to 1760 (1914), together with its companion volume on decoration, she was the first to rediscover English Palladian design, to insist on the importance of historical context, and to rehabilitate the virtually forgotten William Kent (her monograph, The Work of William Kent, appeared in 1948). [...] In the furniture world she had, in the words of Ralph Edwards, keeper of the Victoria and Albert Museum's woodwork department, 'few rivals and no superiors' (private information). Edwards was one of a whole generation of young men, trained by Margaret in the 1920s and 1930s, who went on to fill major posts in the national museums, the National Trust, and the great London auction houses. Younger women whose careers blossomed under her guidance included Joan Evans, Freya Stark, and Ivy Compton-Burnett.

But Amis was never one to shy away from lazy sexist assumptions.