
Hi I have a 15 yr old rough collie and 2yr & 7m old Bearded Collies I tent not to let my beardies around my old boy very much because the puppy wont leave him alone she licks him around the face and jumps at him wanting him to play but eventhough he is very quiet and not at all agressive he gets fed up and annoyed with her so he growls and tells her to leave him alone or else....but she ignores him completely and wants to lie bye him but he is not interested so I keep them seperate and he has the run of the house and they have the kitchen and garden.
I think at thier age they want peace and quiet and dont particularily want to be jumped all over by puppies.
Your puppy sound to me like she is just starting her teenage naughty stage it is definitely not to late for training classes you just have to be consistent with your training and maybe a little more firm but it is a different breed to mine so professional dog trainer would be best for advice.