It's definitely a frequent occurrence. I've been encouraging her to keep better track of her levels and check them more frequently, but she is very annoyed and often feels defeated by the illness so it is difficult for her to stick to that, ya know?
In the past couple months, there have been at least three or four episodes where she was low enough to where I have almost called emergency services. Most recently I tried waking her up for work but she resisted and mumbled, I thought she was just tired and being stubborn. But then I realized that she wasn't responding to my "I love you"s and that sent me running for her meter and food. I can also tell she is high because she will start contacting me online or through text or phone call basically ranting about all sorts of things. The problem I face is that I am still learning about the disease and how she responds and copes with it.
I know one of the hardest parts for her is feeling like she is a burden on me, so sometimes it is almost worse when she comes out of an episode (either a high or a low) because she will feel guilty for either how she treated me during it, that I had to take care and help her during it, or both.