My puppy has just turned 14 weeks old, and until Saturday was being a very receptive and mostly easy puppy. However, on Saturday I took her to a park and she began growling and barking at strangers. I believe it was a fear response but cannot be sure. (Before this out on walks she would just sit down when a stranger or car went past and watch). Then yesterday she began jumping up which she did on occasion, but then biting (not the kind of light kind of nipping, but not heavy bites either. However, she is breaking the skin). She caught my mom legs, with resulted in antibiotics. And today when being removed from the sofa she started, out of frustration, biting on my arms. I could tell she wasn’t happy about being removed, but after Sunday I cannot allow her on furniture until she is trained enough to response to ques. I wanted to get your opinions on her behaviour, because I fear she may be becoming aggressive. I’m still waiting on responses from trainers in my local area, and just feeling really lost and frightened.