After the first round if treatments we waited 3-4 weeks and did the biopsy. After the biopsy came back showing there was still some cancer we waited 3-4 weeks before starting the next round of 6 treatments
I was diagnosed with CIS and had 6 weeks of BCG treatments, when we did the post biopsy I still showed CIS but it was a smaller area then the 1st biopsy showed. I did a 2nd round of 6 treatments that only included 3 with BCG since I had a bad reaction, we completed the last 3 with Interferon alone. The good news is that the 3rd biopsy was clear, no cancer.
The good news here is that your mom has the option to do another round of treatments