Agree about keeping pup seperate from older dog until you know for sure they're ok together. Not all adult dogs, especially females, take kindly to pups that they didn't give birth to being around. I have a Finnish spitz spayed female that would happily kill any pup under 4 months old. I've never proven this but she's made herself very clear. She's fine with them as long as they're not in ''her'' house.
Also, your older dog may be having jealousy issues. If you and your friends are cooing over the cute pup, your other dog is probably feeling left out and not #1 anymore. It helps a lot to pay extra attention to her.