My mom has an abcess on her gums on the upper left side of her mouth.?

She is gonna go to the dentist tommorow for an emergency appointment. My question is do you dentists think this is good enough? Should I take her to the hospital tonight? Shes in alot of pain and i know mouth infections can cause people to become septic and/or spread to the brain and heart, is it safe to wait till tommorow for treatment?