I've been riding since before I could walk, my mom (was a trainer & taught me a lot) is insanely critical, a 1/16th of an inch in the wrong and she's all over it. She still makes me slightly nervous when she watches me ride. She doesn't hold back and will nitpick any mistake she can find. When I was younger all it did was piss me off and cause us to fight, now I ask her to come watch me work youngsters every once in awhile and pick at me because I can use it to my benefit. Even though I may not like what she has to say sometimes, I'm better for hearing it.
Just keep working hard and take in what is said if it's worth hearing and if not let it roll off. :)