Female Terrier, Pit Bull/Mix named Mozzie available for adoption

Mozzie is a young, nice and energetic girl, she's good with people but she will also jump up on people and run around. Why I sent her back is that she to started to become reactive on leash with barking, growling and pulling hard, It was difficult to change direction because she was focused on the other dogs, now I won't send her out with volunteers because my fear is that she will pull someone down or a volunteer may let go because of the pulling . This is a new behavior, until today she was fine on leash passing other dogs, she always pulled but not to this extent.