How does one perform the Udyapan (feeding of eight boys with kheer and gram curry) after completing the 16-week Santoshi Mata fast, if one does not have family or friends to partake? Is it possible to have this done at a temple?
Yes, you can perform this Udyapan at a local temple. Call the priest and ask how he or she can help you organize the puja and what would be appropriate in their tradition. If you choose, we could help organize the puja here.
It has been mentioned that if one keeps a fast for eight continuous Saturdays, that Santoshi Maa has never failed to give Her devotees the desires of their heart. Could you please give me more information?
That is written in Her Katha, the story of Santoshi Maa. However, the devotee requires the right motivation, the right concentration, the right planning and execution. But, yes, it is written.