Laura Conner's doctor says that she accidentally took 24 mg of Dilaudid (hydromorphone) once, as she was taking the standard therapeutic dose and then forgot she had taken a dose already, and then took the second pill. This would mean her prescribed dose was 12 mg, which is quite a bit higher than the standard dose that would be given to a regular patient. Mrs. Conner was apparently a long-time user, which explains why she was taking such a large amount, but it certainly isn't a "standard therapeutic dose". Hydromorphone is about four times more potent than morphine, with a normal dose of 2-4 mg every four to six hours; the immediate release tablets come in 2 mg, 4 mg, and 8 mg strengths, with the 8 mg strength only prescribed to opioid tolerant patients. 24 mg would actually be a dangerous dose for someone to take all at once, and while it probably wouldn't be fatal to most people it would certainly cause respiratory issues, severe disorientation, and sedation. Furthermore, with the strengths available she would have needed to take more than just two tablets; the 2 mg would require 12 tablets to equal 24 mg, the 4 mg would be six tablets, and the 8 mg three tablets.
