I am in need of advice, i have an opportunity to help a 4yr old mastiff rescue, she was abandoned at an early age, then adopted and surrendered back to the animal control without reason. She sweet, and smart but has issues. I know she needs exersize and training. I have experience with larger stronger dogs but want to know more about this breed. She is a jumper, and very mouthy but not aggressive in any way. Gets overstimulated very easy with touch and distraction. And is up on counters all the time. Shes very food motivated. Knows basic comnands, sit, and does not pull on leash. My question is at 4 are these issues going to be correctable with patience?