Cjr
With mixed insulin she cant control the doses the same as a basal/bolus routine (which is when you get insulin to last for a 24 hour period (basal) and then insulin to inject to cover food (bolus). Forgive me if im repeating what you know, im not sure if this was mentioned to your or not and didnt want to use jargon you werent familiar with.
Due to this, you might find that she needs to snack mid morning and again mid afternoon to 'meet' the insulin's peaks and troughs and to avoid hypos . As hanadr says, it is very individual and testing is the best way to find out. I am on similar regime and find I can get away with a morning snack but not afternoon, or else I am guaranteed a hypo or near miss before tea time.
The downfall of this regime, if any, is that you cant necessarily control bg after eating as well, and I know that I avoid cereal bars like the plague - they always raise me too high. Maybe give her one at the weekend, test and see how it impacts on her then decide?
Nuts are a good replacement, but not as convenient I suppose, but if she can tolerate it, oatcakes and peanut butter, or something similar. Holland and Barrett do peanut butter with no added sugar, so its much better than some supermarket brands (Glucose is 2nd ingredient in Tesco's peanut butter!!!)
She sounds like she's doing great. Much braver than me when I was diagnosed
