I hope that by now the bleeding has slowed down considerably if not stopped altogether. If it hasn't I would strongly suggest she see her dentist ASAP.
As a relatively new denture wearer I would just like to add a few suggestions to help you mom get through the next few days. She should rinse her mouth with salt water often. This will help keep the gums clean, rinse away excess blood and has the added bonus of having a bit of a soothing effect on the gums. Preferably, she should keep the denture in 24 hrs/day except for cleaning and salt water rinses until the dentist says she doesn't need to wear them the entire time anymore. I wore mine 24hrs/day for almost 2 weeks. The post about the denture acting as a bandage and for swelling control was right on the mark. So was the post about taking the dentures out if they cause pain. If the gums are painful try to determine what is causing the pain. If it is general pain from the extractions or swelling pain killers should work well enough until some healing ocurrs and some swelling goes down. Painkillers however, will not help if the denture is rubbing or aggravating the gums or other part of the mouth in some way. If it is the denture causing the pain your mom should see the dentist within a reasonalble time period to have the denture adjusted. She should wear the denture for 8 to 12 hours before seeing the dentist so he/she can see any inflamation where the denture is aggravating the gums or mouth. She should go back to the dentist as often as needed to resolve any sore spots. It's very important at this early stage that sore spots are treated promptly and the denture be comfortable in her mouth.
It's important that your mom be patient with her healing gums and the new denture. Healing takes time and so does adjusting and learning how to cope with the denture. It's also important that she follow her dentists instructions. It may be uncomfortable and sometimes a bit sore but it is in her best interests.
If you or your mom have any other questions please ask. There are at least a couple of new denture wearers here
Tell your mom I wish her luck.