I am so glad that your little baby is okay. There was a story about this on Emergency Vets on Animal Planet once, but the child was only 5. She may have seen it or she may be acting out her issue with being away from home for the summer. I am a step-parent, and it is hard. I hope that you two can find some common ground or it could be a long summer. Sounds like your step-daugher needs some TLC and some help with her feelings about her situation. Good luck, and I hope that things go better for you and your poor little puppy. I would definitely make sure you supervise them both.