Teacher feels daughter isn't mature enough for fourth grade?

Our daughter is the youngest in her cl. She made the cut-off date for Kindergarten by one day. She did ok in most of her cles; but has a hard time with some math facts and concepts. Because of her age, teacher feels she is socially immature to p on to fourth, for reasons such as not following directions, listening, talking out of turn, tattling, etc. Husband and I don't want to hold her back, since she did p all of her cles. In math, she went from an F to a C-, to a D for failing two major tests.