Who is Clarice Rumfoord from Welcome to the Monkey House and what is their importance?

Clarice Rumfoord appears in the beginning of the story as a tight, tense woman, the only Rumfoord who doesn't look like a bear. The narrator notes her tension and terseness for most of the story, until Robert brings Sheila home to dinner. When she hears her son is engaged and is quitting politics, Clarice immediately looks younger, calmer and happier. She is even happier when the Commodore mentions that he will need to go back to work now that Robert will be gone. Clarice bursts forth with a comment about how she has trouble admiring a man who doesn't work. The impression is that Clarice has been holding back her objections to her husband's obsession with Hyannis Port and the abnormal existence that has sprung from it, and that it's been taking a toll on her life.