It sounds like Rosey needs some guidance on what is and is not considered appropriate behaviour for a puppy. Puppies use their mouths to play and to explore the world around them, but need to learn that it is not ok to bite humans. It is important to help her develop bite inhibition and redirect her to an appropriate activity, as well as to teach her that biting humans means they won’t play with her until he calms down. Visit the following link for more information on how to work on these goals at home
https://www.aspca.org/pet-care/dog-care/common-dog-behavior-issues/mouthing-nipping-and-biting-puppies. I also strongly recommend working one on one with a reputable trainer to help set boundaries for Rosey, as basic puppy classes at a pet shop are good for socialization, but may not be enough to address Rosey’s biting problem. Visit
https://www.aspca.org/pet-care/general-pet-care/behavioral-help-your-pet for information on how to find behaviour help near you. You can also work directly with a board certified veterinary behaviourist, as they are the experts in the field, and have resources and training available that make them the most likely to be able to help Rosey. See the following link for more information
http://www.dacvb.org/resources/for-the-public/Regular exercise and enrolling Rosey in a puppy class to help her burn off some excess energy and learn how to play appropriately are also important steps you can take to help her succeed. It is also essential to make sure she is up to date on her vaccinations, particularly her rabies vaccine, as a dog who bites (even in play) can be a potential health risk for animals and people around them.