Reaction time to an intake of carbs or more specifically glucose does seem to vary between individuals. It also varies with the type of glucose – sweets, tablets or juice one takes and also to what one is doing as exercise can impact significantly. For a while I stuck to the ‘retest after 15 minutes and if BG hasn’t risen take more glucose.’ But discovered that it takes longer than 15 minutes for me to react with the consequence that I would take more carbs/glucose and then end up with my BG rocketing skywards.
The quickest fix comes with carbs/glucose in liquid form such as Glucojuice or’ Lift’ as it doesn’t have to dissolve in the digestive tract. Sweets per se vary in carb content, Jelly Babies are a bit over 5g each so eating 2 should in theory bring your BG up by 2 to 3 mmol.
In your particular case at present, I'd suggest you don't panic as your BG will start to rise after those sweets!