It definitely helps me to inject at least 15 minutes before meals, reducing any post meal spikes. How long before is one of thos fluid things, I think, where you have to take account of various other factors. For example, I test and if I am a little on the low side (4.x) then I will inject closer to eating so I don't drop low before the food starts digesting. Obviously the type of food you are about to eat also needs consideration - I have been caught out when injecting too early for a fattier meal that took longer to digest, so the insulin started to peak before my food. Also, the time of day can be a consideration - in the mornings I am quite insulin-resistant and can inject anything up to 45 minutes prior to eating and not drop low, but obviously this is just me and may not be true of others. Later in the day I'll try to eat within 20 minutes of injecting at the latest.
I think that starting at 10-15 minutes before is a good idea (taking account of levels, of course) and then learning from experience. 🙂 Of course, one of the problems with such a young child may be that they might not be hungry or want to eat the food 15 minutes later and whilst a solution might be to give a split injection, that's a bit unfair to give extra injections to her!
