Hi Kim,
You sound a lot like I did 8 yrs ago when my sister was diagnosed with what sounds like the same thing your mother has. She also goes to Sloan. I was also confused when the doctor removed the tumor and advised no further treatment. After many months of research and networking, I came to understand the hows and whys of his approach and now I'm glad that my sister never received other treatments. She had a couple of recurrences the first year (who knows, they might have been leftovers from the TUR and not true recurs...even cystoscopy misses up to 10% of tumors~).
You got input from others here of the subject of re-TURs, understaging and other concerns. If the tumor is staged at T1, then re-TURs are strongly advised to removed residual tumor, followed by immunotherapy/BCG (most of the time). The most important thing is what the pathology report says, so please let us know how that turns out.
Good luck with things,
Wendy