In addition to the good words of wisdom written above, I'll just add that if you associate the new puppy with really good times and good treats to your other dog, that can improve her opinion of him. Whenever the pup comes around close, give your other dog a super tasty treat and some extra attention. When puppy is not right there in the room or too close, make things a little boring. In other words, "Wow....this puppy is terrific to have around. All kinds of great things happen. Things are looking up. I sure like this puppy." LOL.
Also, be sure to not only take them on walks together, but have some one on one time with each so neither feels left out. They should both adjust with time, patience and gentle handling. Good luck.