Final answer:
At dinner with Don and Bev, the Roses encounter their mother's friends, artist Richard Demming and Mr. Edgeworthy, who is an old acquaintance of Elizabeth.
Step-by-step explanation:
The Roses run into two of their mother's friends at dinner with Don and Bev. These friends are described in the excerpt, with Harry introducing Mr. Richard Demming, the artist, and mentioning that Elizabeth and Mr. Edgeworthy are old acquaintances. The dinner scene appears to be a social setting that combines characters with different backgrounds, possibly suggesting themes around social interactions, perceived social status, or even estrangement.