I think she will be shaking either because she is excited or because she is afraid. You'll be able to tell which it is, by her behaviour. She is a very little baby, remember, and absolutely everything is new to her. You don't need to 'be tough on her' - just consistent, and kind.
Be careful about saying no - it is a very general word, and we use it to mean a lot of things - no (don't chew my shoe), no (don't eat the grass), no (don't jump up), no (don't go in the cupboard). And these multiple meanings can be a bit hard for a baby puppy to understand - basically although you say she understands 'no', she really won't have any idea what you are on about. She will understand your disapproval from the tone of your voice, and know that you are not pleased with her.
I think you will find it much more effective to distract her when she is doing something you don't want her to do, and use positive reinforcement for desired behaviour instead. Call her, praise her like mad when she comes to you, offer her a toy as an entertaining alternative.