Your friend is right, blood work and urine are totally different but usually if anything is wrong it may show up in blood work.
I'm older then your mom and like I said, have had this going on for years and went through many tests, just had my urine tested 2 months ago again. My Dr. keeps on top of it just in case anything shows up.
I also had a hysterectomy at 39 due to a tumor and dropped bladder but all went fine and nothing wrong was found. Don't jump to conclusions till tests are done or the Dr. feels something is wrong. The bacteria could be from a cold or even an intestenal cold/virus infection.
Best to you and your mom...JJ...