No one can tell you how big they will get, you didn't say what the mom is, nor do you know what the dad is. Are the puppies keeping their weight up? How old is the female? Only two puppies? All I can say is, after this litter.......get her spayed. I remember growing up, my parents let their Collie roam the neighborhood. She ended up pregnant by who knows how many different dogs over her life time.. We never knew who the "dad" was.