We have had her since a pup. She started the jumping and biting a month ago. It doesn’t break the skin. We are in our early 60’s and my husband is home with her all day. This is our 3rd large do we had a lab and a shepherd mix before her that each lived12 yrs. We give her lots of attention as she demands. Our lab was high maintenance as well but never nipped. Sometimes if she’s had too much petting or not in the mood she will start to nip. We love her dearly and do not mistreat her. She has lots of toys and she gets a bully stick for 10 minutes each night The aggression may be to show dominance. We just don’t want her nipping to become ingrained