DS tells me my Mom doesn't seem to get that he has to count carbs, not just sugar. She will tell him "don't forget to see how much sugar is in that (whatever)" instead of having him look at the carb content. She loves him and she means well, she just doesn't seem to retain the info that carbs are the important "thing" he has to keep track of. To her, sugar is what matters.
Coworker may just not be retaining the info you gave her about carbs - thinking "diabetics can't eat *sugar*, or need to keep track of *sugar* intake" seems to be a very common misconception. We didn't know either, until J was diagnosed.