well, i can find that your friend has two miscarriages in the first trimester and her uterus is big than expected,.
i think she need to do an transvaginal ultrasound
scan to know why the uterus is big and certain other tests such as a diagnostic hysteroscopy
to find out any structural anomaly such as a septa or a myoma or adenomyosis
,former two are correctable causes of pregnancy
loss. A myoma /adenomyosis of uterus can cause heavy flow with clots . She can also undergo an thyroid profile and antiphospholipid antibody titre of her blood.
Well good luck and don't get disheartened.
bye, take care