Help me find the book title !!?

Hi everyone!! So I am stuck at trying to remember this book title and I need to find the book. if anyone can help thanks ! I remember the cover of the book was kinda green with an dirty white/yellow dog on the front. It was about a girl who was in an accident and I believe her mom died ? and she was really struggling because all friends were out having fun during the summer and she couldn’t. Then a stray dog started showing up and she started working with him. it took her the whole book but she did it. I remember there was a point in the book where she just starts walking and he follows her. and eventually he comes in her home willingly and soon she names him. the dog gave her something to do during the summer and she would talk about how much she would be sweating and her clothes would be drenched and how bad her legs would feel after working with the dog. She named fhe dog but I cannot remember what it was.. at the end the dog was living with her. I know that’s not a lot but ugh