Who is Mother Shaum from Citizen of the Galaxy and what is their importance?

Mother Shaum is one of Baslim's good friends in Jubblepore. She is the one person Thorby can go to for help after Baslim's death, and she immediately assists him by getting a message to Kraussa on Sisu and helping him with transport. Thorby has to be smuggled off od Jubblepore because of the danger.