470 is definitely a high blood sugar. For type 2's, I believe the recommended range is 80-130. I am type 1, so I'm not 100% sure of that range. Is your mother on oral medication? If not, her doctor would likely recommend that before trying insulin shots. I know that going on insulin is a huge fear, but sometimes that's what it takes to keep things under control. It doesn't mean that you are bad or your diabetes is bad. Insulin is just another tool in the diabetes management arsenal. Best of luck to your mother and I hope she and her doctor have a nice discussion.

470 is pretty high, almost dangerous. The question here is how often is she reaching these high numbers. If she isn't taking any meds, then possibly starting some may be helpful. If she is on oral medications, the doctor may consider altering her does. Insulin may be considered if these meds aren't helping.

While taking shots are not fun, having high numbers like this persistently can put your mother at risk for more serious complications down the line. I would really push for her to talk to her doctor.

She NEEDS to tell her doctor ASAP. Don't wait for the next appointment, call the doctor and tell her/him. If your mother is not on meds, she needs to start first on tablets - there are several drugs that can help bring the blood glucose level down. This high level WILL cause complications unless dealt with. The least unpleasant of those is damaged eyesight up to blindness. Wikipedia has an excellent link textarticle.