Hiya, sorry to hear about your daughters loss and yours as a grandparent to be.
How many weeks was she and which miscarriage management did she undergo?
I miscarried naturally at 10 weeks in March and a week after I had a scan to check all was well - they said the lining of my uterus was pretty thin (around 6mm) so my next period should be about normal, which it was, though I did lose a few clots which I dont usually.
I have just sadly miscarried again (I had that one period then found out I was pregnant again), this time at 9 weeks - again miscarried naturally, albeit very differently and a lot more traumatically from my first miscarriage with massive blood loss and A&E admittance via ambulance.
However, my follow up scan, less than a week later, showed that my uterus lining was still quite thickened at 11mm and was advised that I would probably bleed quite heavily on my next period. Apparently anything over 14mm and they advise ERPC.
Maybe it may be best for her to phone her GP or the EPU for advice? As I lost so much blood I am now anaemic so it may be just as well for your daughter to get that checked out anyway?
Hope this helps x