For months now she's been a wonderful dog and showing real good signs of maturity but over the last weeks she's been an absolute nightmare! She's started getting on furniture again, being a nightmare to walk as she's started pulling again, chasing everything that moves and getting silly by darting around in circles and lead chewing again, is this a sign of the terrible teens?! She's coming up to a year old. We are getting her spayed next month, would this help calm her down a bit? Or is it just a case of going back to basics?