The minute someone fails to meet your expectations, take a deep breath and say, "She is NOT perfect."
I adamantly thought that I do not seek perfection in people. I thought I was rather patient, kind, and gentle... But when I carefully observed the way I thought about my mistakes and people's, I totally contradict myself.
Are you hard on yourself when you make mistakes?
Are you hard on OTHER people when they make mistakes?
Do you impose your standards on other people, hoping they get on with the "program"?
Do you think negatively when people disappoint your expectations?
Well, there you go.
Perfection nullifies your need for grace.