Lady Alice is described as being a "plain woman", but "quite a pleasant one". She is a "thin woman with sandy-coloured hair, a well-arched nose and vague, hazel eyes". Her voice is well-bred, monotonous, and rather depressing.
Harold had not been in love with her, but had married her because he thought her family would have been nice relations for any sons they may have had. However, they did not have any children. They had nothing in common, nothing to talk about, and no memories to share.
Lady Alice often stayed away with relations, and usually went to the Riviera in the winter. This suited both her and Harold.
BBC's Miss Marple
In BBC's 1987 adaptation of 4.50 from Paddington, Alice Crackenthorpe does not appear on screen but Miss Marple does visit her in London. There she discovered that her late husband (he had already been killed) had an interest in ballet and their house was filled with ballet memorabilia including a poster advertising the last English tour of the Ballet Maritska.
ITV's Agatha Christie's Marple
In ITV's 2004 adaptation of 4.50 from Paddington, the part of Lady Alice is portrayed by Rose Keegan. In this adaptation, she has a larger role and does come down to Rutherford Hall with her husband. She comes across as snooty and snobbish, concerned about her expensive clothes. In one instance her Dior outfit, says her husband, is worth a year's membership at a golf club and some good cigars. Nonetheless, the relationship between her and her husband is not as strained as described in the original novel. She appears quite fond of Alfred, or at least holds up up in front of others, telling others that he has a "very responsible position" in her father's firm.