Most Helpful Girl
Yes, this is totally normal. No relationship is perfect forever and you all just got out of that infatuation stage that is always short lived in a relationship. You don't want to smother one another 24/7, because that just drives the other person away. So yeah, she may want some fresh air every now and than. It doesn't mean she doesn't love you. So don't be depressed, it happens to the best of us.
Most Helpful Guy
Just keep showing her love and affection. Live like everyday would be your last.