Should i let the puppy walk down the stairs herself?
Up is usually easier to learn than down stairs. Let the puppy go up the stairs but with you beside her and her against the wall, not by the banister. Then when she gets a little older and less clumsy, then you can let her go down a few steps, not from the top, so if she falls, it won’t be so far. Then as she gets the hang of it you can let her go down from a few steps higher until she can go from the top.