RIRS DJ stenting. A role in the surgery?

Mother was hospitalized in early March. Mri and blood and urine test showed infection in kidney and wS treated with antibiotics IV for a week. Follow up CT scan after 2 weeks showed a 6.3mm calculus near VUJ. Doctor gave medicines to help pass stone. Follow up after 2  weeks CT shows the 5mm calculus with mean attenuation of 700-800HU at VUJ with upstream mild hydronephrosis. Doctor has suggested RIRS + DJ stenting to remove the stone as it is causing obstruction. How safe and effective is RIRS? My mother is diabetic. Also she hasn't felt any pain or discomfort since the discovery of the stone. Her present urine analysis shows pale yellow, slightly hazy and 6-8 pus cells and bacteria detected. Culture shows E. coli significant bacteria. Does the presence of active UTI play a role in the surgery? Please tell me