My 84 Year Old Mother In Law Had Endometrial Cancer

My 84 year old mother in law had endometrial cancer and had robotic hysterectomy in late March. She recovered well and told that she didn't need any treatments due to cancer not in the wall of uterus and all labs looked great. Now she has a tumor in the vaginal cuff and another one lower on the vaginal wall.
She is doing 5 internal radiation treatments to just radiate those specific areas. All good but today I took her to radiation for 1st treatment and doctor was concerned as she was that she was bleeding vaginally. Quite heavy - not just spotting like she had been... my question is this normal? Do the tumors bleed? She doesn't have a uterus so it's not coming from there.... how does this work?