I was so embarrassed at work last week.  My boss keeps bringing up a mistake I made months back.
That happens, you have to acknowledge mistakes to learn from them.
I did though, I've apologized repeatedly.  we've discussed it multiple times.  It's hard because she brings it up in front of others. 
Oh well that seems improper, you should bring it up to her supervisor.
She doesn't really have one.  She's the PI and her technical supervisor won't do anything.  