Honestly, she's a puppy. Bully's can be very "mouthy" and our puppy has been extremely mouthy at times during play or when we first get home. She's starting to improve, but it takes time, patience, and consistency and I'm sure Matilda will get there. When she does bite, redirect her to a toy if you haven't tried that already. We've noticed that our Ellie Mae seems to do good with plenty of chewing options. One day she'll play with certain toys and the next might be a completely different set that she drags out of her basket. Just keep working with her and correcting her when she does bite too roughly.