She sounds like a pretty normal Rottie puppy to me. ALL puppies love attention, why would you think at 3 months old that she should hear you and "know" you don't want her to interact with? She's a BABY. You have two puppies with different temperaments, is all.
You should be giving attention to and working with each of these puppies separately, for the most part, with a measured amount of "group" play. Plan a time each day for that, and when you are working with one of the puppies, put the other in a crate so the puppy you are working with has your undivided attention. Then switch and work with the other puppy. Same goes for walks - take them one at a time so you can work with one puppy undistracted by the other. Each should be taken to obedience classes separately by you. Raising two puppies at the same time is 3 times as much work as raising one alone. You have your work cut out for you!
