You got some great advices so far and I would add one more thing, specifically what to stay away from in case of ulcers. You should ask your mom's doctor to be sure but if I know correctly your mom should be very carefull with "Non Steroidal Anti Inflammatory Drugs" like Aspirin, Advil, Motrin, Ibuprofen. These are pretty common pain medication, and they have been linked to cause ulcers and I'm sure if ulcers already exists would only worsen the situation.
I trully that hope your mom gets better, ulcers are not to be taken ligthly.