In the stage play Love from a Stranger (which is derived from the short story Philomel Cottage, Mavis Wilson is a friend of Cecily Harrington. They share a flat in Bayswater, London. This character does not have a parallel in Philomel Cottage. Mavis's role in the plot is mainly as a conversation mouthpiece, to allow certain background information and thoughts to be presented to the audience. In the first act, for example, she is shown packing up her flat and preparing it to be let, with the help of Cecily's aunt Louise Garrard. Their conversation informs the audience about Cecily's recent win of a large sum of money and how he fiancé Nigel Lawrence would be coming back from overseas and that they would be getting married soon.
Mavis also answers the phone call which introduces Bruce Lovell who comes over to view the flat as a prospective renter. Later when Cecily is smitten by Bruce and breaks off her engagement with Nigel and plans to marry Bruce, Mavis is a sounding board for both Nigel and Cecily.
In Act 3, after Cecily's marriage to Bruce, Mavis visits Cecily in her cottage, and this gives Cecily a chance to express her concerns about how Bruce has changed.
Stage directions describe Mavis as a pleasant, calm-faced woman of about thirty, with a firm manner.