This is our second puppy and we also have a four year old. Maybe it's just that we know more what we are doing this time - but Macey seems VERY quick to learn compared to Jake. She was 3 mos when we adopted her (now 4 mos). Within a week, she was going to door to go out. She learned sit, paw and down in the first and second week and has figured out-stay and leave it without our knowingly "teaching" it. She has also learned to stay away from big brother if he's not in the mood for her.
She is so calm compared to how Jake was. She doesn't even jump much when greeting us - no crying in crate, no whimpering if we're not in sight, she's just soooo sweet!
Here is a pic of her with big brother...

For me she is a fast learner dog...she learned things and command in a short period of time...your dogs seems great even though they are different in behavior...

great as long as they work out their differences eventually,they are both great in their own ways. Funny how as a pet parent we still have pride in having a smart pet!

First off, I just want to say what a great pic that is of your dogs. Your pup sounds pretty bright and good-natured, much like my Gunther was as a pup. Although I've found judging our dogs' intelligence can sometimes be a laughing matter. When I brought Gunther home at eight weeks I thought he was the smartest puppy on earth. Every so often he would come to me carrying his water-bowl. I thought he was letting me know it was empty and that he was thirsty. Turned out, with later observation, he was dumping the water out himself and just playing with the bowl. So much for my little Einstein

My 16 week old puppy knows Sit, Down, Stay, Roll-Over, Dance, Paw, Kisses, High-Five, Housebroken, Crate Trained, etc....

ALL puppies are extremely smart... owners aren't, hahaha

You are now more experienced and are giving the puppy proper care. The dog is also learning through Social Recognition from your older dog.

Example: If I say "Down" to one of my dogs, then they all look at her and copy. This shows they all respect the balance of our pack.

Having control of the whole pack shows good Pet Parent leadership.

Every breed and every dog is an individual, just like children. To compare one to another is like comparing apples to oranges. Some breeds are more willing to please than others, as some dogs are more stubborn and head strong than others. It sounds as though your new pup has a good head on her shoulders, best wishes with her.