How much crying without being tended to do you think is terrifying? Most sleep training I have seen says to let them cry for up to 15 minutes before getting th

How much crying without being tended to do you think is terrifying? Most sleep training I have seen says to let them cry for up to 15 minutes before getting them. We usually let ours cry for up to 5 minutes before picking her up. She would rarely cry for more than a minute or two before just falling asleep.