What both of the two above writers offered is good, and I’d like to add a little more. Certainly you are learning and being able to know to ask questions is a great sign and intelligent; just like 18 months ago when you had a new daughter - hope she is well.
As @Joe offered “carb counting” is key to management and then applying the ratio that YOUR body requires for that time of day - for instance, I currently need one unit of insulin for every 8.5 grams of carb I eat at breakfast [ratio 1:8.5] but only need one unit for each 17 grams of carb at dinner [ratio 1:17]. Our bodies are all different and you will need to calculate, by experiment, what you require; and nothing gets “locked in stone”.
I will suggest that if you are really low, that you have a measured +/-15 grams of carb and wait 15 minutes and recheck your BG - never take insulin before you do a second check. Over years experience, I’ve learned if feeling woozy it is best to eat / drink first and then check BG. When I’m out and about, I always have at least one small granola bar with me - 17 grams carb including intermediate range carbs. Be cautious about taking inulin when you are below your safe range, especially when you are alone with your daughter; well until your daughter is like ours, a medical professional.
When someone is depending on you or when you are alone, being a little over range is much safer than being below range.