Actually, it would appear that it was closer to a week and glucose levels are high even after taking insulin so it is definitely an issue :(
Anyway, hopefully its not too bad now...
Thanks for the information, she definitely feels it if her sugar levels are too high.
So she must have been in the honeymoon period then, I'll advise her to buy a backup meter for next time.
She has been diagnosed with type 1 for about 10 years now!
This is extremely dangerous behavior. What can happen is that the person can go into DKA, become very ill and need to be hospitalized; in a few days they can die. At the very least, remaining at extremely high blood sugars for 3-4 days can lead to complications down the road that are very serious. I would suggest your friend buy a back-up meter or at least if this happens again she not wait to get back on track.
The explanation for why she didn't become ill may have to do with what we call the "honeymoon" period. Some people continue to produce some of their own insulin for a period of time after diagnosis, but this doesn't last.