Who was the devotee Sai Baba called 'Mother', and what was her role in the story with Anna?

The devotee Sai Baba called "Mother" (Aai) was a woman named Venubai Kaujalgi, though everyone else called her Mavshibai. According to Chapter 24, she was a widow of mature age with an incomparable devotion to Sai Baba's feet. In the story, she is serving Baba by vigorously massaging his stomach. Her role is that of a humorous provocateur; while swaying in her service, her face comes near Anna's, and she jokingly accuses him of wanting a kiss. This sparks a quarrel that Sai Baba ultimately resolves by humorously siding with her, reinforcing her affectionate title of "Mother."