At first, frequency is more important than length of time practicing. You are training your fingers to do things never intended by nature. It takes time to develop good habits and muscle memory. At first you will have to think about every movement, but with sufficient regular practice many things will eventually become habitual.
Give your fingers a chance to form good habits. Accuracy trumps speed. If you practice too fast you will only succeed in reinforcing your mistakes.
If you don't practice you will not improve, and you will risk losing your place as a student of Mrs. King.