Will my dog protect me when she grows up she only 4 months old now great pyrenees/mastiff mix?

ive had her for about a month or two great dog knows how to sit lay down stay very social when family or friends come doesnt ever bark unless someone walks by the house also curious how big she will be she is 20 inches at withers and 50 to 60lbs healthy looking and she stays inside my house with me sleeps under my bed