she should go to the doctors really as she may need a course of anti - inflammatories or steroids to dampen down the inflammation. No one can tell you if it is serious or not without knowing the history, but anything to do with jaundice should be directed to the medical profession for their help. It could be simply managed or it could mean her blood counts need monitering and she may need regular medication. I personally would not advise any alcohol at all whilst jaundiced.
sorrry to hear this about your mom. Your mom definitely needs to stay away from having any alcohol. She also should see a "Hepatologist" - Liver Specialist, found at larger teaching Hospitals. The Hepatologist will give her a complete exam, possibly liver biopsy (nothing to it, I had one) and find out exactly what the problem is.
Good luck.