I think you will find that the advice nowadays to bring blood sugars up quickly is to use liquid if possible. Sweets without fats in them are recommended too. The thing to avoid is using anything with fats in it as this slows down the absorption considerably.
And like others say, all you can do is experiment with how much sugar brings the BGs up by how much. Unfortunately, you can only find that out by trial and error. I have no experience of treating children - I was 17 when diagnosed a very long time ago - but I believe I am right in thinking that ratios of sugar to BS levels will be much smaller in children who have smaller bodies than adults, so the average level for grown ups of approximately 10g of carbs raising the BS by 2 or 3mmols would be likely to be a bit less for children. So experiment is all you have. That goes for all of us: there are no absolute ratios that are the same for everyone.
Glucose will work quicker than anything else, but dry glucose, like glucose tabs ,is very hard eat as you get a bit of a dry mouth with a hypo and you need water to help absorb them, not to mention swallow them. Glucose needs no breaking down in the body because it is already in the form that all carbs are broken down to by the digestive system, in order to be absorbed from the blood. So a drink with neat glucose in it will work in seconds where a fruit juice drink will take a few minutes to work as the sugar in that is fructose which has to be worked on by the body a little before absorption. Either way though, the reaction is very fast. Having said that, although Lucozade is mostly glucose, I gave up trying to use it long ago for two reasons: more than a few mouthfuls is too much and you can't buy bottles small enough, and it is, for me, very hard to gulp its extreme fizziness quickly because it hurts.
It's worth taking exercise into account, as well as the timings that others have mentioned. If the hypo is after exercise, then the BS could be still dropping and need a little more to recover, where if your daughter has been watching TV or sitting in class, then you might not need so much. Sometimes when you test, you might find the BS low, but you cannot know whether it is actually recovering on its own, or is still going down. If she was a bit low, and has not been hypo for a while, the body is likely to be releasing its own supplies of glucogon to right the situation, so the recovery will be a bit more dramatic than expected. However, you must never expect that to be happening and not treat a hypo: that could be dangerous, and it's far safer for the BS to go a bit high for a short time than to leave a hypo untreated. It is quite normal to get a post hypo high and the Powers that Be generally tell us not to worry about it, and not to treat it because if you do you can start a roller coaster of BS levels which is a pain and quite hard to get back under control.
Good luck with it all.
