
You haven't mentioned what breed your adult is
If you comfort your puppy you are telling her that it is alright to be frightened & make a fuss
I personally would not leave them alone together & make sure that your adult has a place to escape & vica versa
You also have not mentioned where you got your puppy from & whether or not she had seen adults other than her mother.or whether the breeders had handled the puppies & allowed them to meet adult dogs of their own
I have never had a problem like this as my adults are used to having a puppy around & although my males usually avoid puppies until they are around 6 months old & they leave the social skills training to my bitch(was bitches until last year when I lost my older bitch)
It does sound like your bitch hasn't had much dealing with puppies so might be worried or the opposite overly rough with a puppy(not in a nasty way) My very big GSD bitch insists on playing with all new puppies that come here. but she has always been very gentle with them even though she was rough when playing with my late BCs(they were the adults when she joined the Household)
Can you give anymore info ?