It is very common for kids not to respond as well to their parent as a teacher. I could not get my son to properly hold a pencil and write his name, but as soon as he started preschool, he did beautifully with it.
Of course, on other things I can teach my son better than anyone else. But there are often certain things that someone else can really help with, so don't feel bad about it. This is just one of those things where she might respond much better to a different teacher.