Hi Hugo Your puppy isn't being a 'bad puppy' she is simply playing and following her natural canine instincts.
This is one of the reasons why I don't recommend pee pee pads when you want to Potty Train A Puppy, they generally end up as toys and the whole process confuses the pup.
If at all possible I'd recommend that you stop using the pee pads and begin to housebreak your pup to pee/poop outside. If this isn't possible, then a doggie litter tray, such as the Rascal Dog Litter Box or an indoor potty like the Mini Pee Wee indoor portable dog potty are much better choices.
If this is your first puppy I think you may find this page useful... New Puppy Care. It has lots of tips and advice to help you understand and take care of your new four-legged family member.
Hope this helps, I wish you the very best of luck with your pup.