Vaginal bleeding with large clots past menopause

Patient: My mother, who is 68 years old and at least 10 years post menopause has had heavy vaginal bleeding and has passed several egg sized clots. This has happened 3 times this week and it only passes when she is sitting on the toilet. She is not on hormone therapy, not obese and does not have a history of fibroids. She is in a rehab facility due to shoulder replacement surgery and the nurses there do not seem concerned, but I am. Are the large clots a concern? She doesn’t seem to be at risk for the other causes of vaginal bleeding that I can find on the internet but I don’t see any mention of large clots in the description of symptoms. I know thinning of the vaginal walls can a cause bleeding but can it cause the large clots? Thanks in advance.

Symptoms: Vaginal bleeding, large clots, post menopause