Ok. A few minutes around Jane and I went to my friend's house. Because they got a new yorkie pup(lucky them)

. While we got the my friend, Star brought the puppy out. Jane began to growl. I was shocked. When the pup tried to come near Jane but she snarled and growled and ran behind me hiding for her.
I got worried. If I get a yorkie will Jane be like that? I love jane but I am also worried that what if I am gone and its just Jane and the puppy. What would they do? Would Jane hurt her?
I am so confused. Please help me!