Not so sure what the difficulty is here.
48#s - 88#s is standard.
Height at the withers: 60 cm to 65 cm
Weight: 30 kg to 40 kg
Height at the withers: 55 cm to 60 cm
Weight: 22 kg to 32 kg
Time itself is a very powerful component of learning. So learn to wait. Learn to forgive. Learn to backup. It's all necessary for learning.
Teach! Teach! Teach! Be fair to your dog!