My 2 boys are still very excitable and they are 2 years old. I think little dogs calm down a little later in life bc they have a longer life span so they have a lot of energy for more of the earlier years (total theory here, at least thats what I tell myself when my dogs are NUTS!! LOL)
Sounds like Sammy could use a little more authority and training though too. My boys are nuts, but the groomer says they are good when they are with her. They do not nip at all, but they are always underfoot like sammy... I think its a yorkie thing, they just want to be WITH you all the time!!
Id work on the nipping thing, gently but firmly hold her snout shut and say "NO BITING" in a firm voice, you dont need to yell just be firm. Make sure everyone knows to do that so everyone is consistant in her training and she'll catch on quickly. They are very smart!
As for walking on a leash, if you want her to stay with you, give her only enough wiggle room to stay at your side. When I walked my dogs on their leashes I let them have all the room and they were sooo hard to walk, they zigzagged a lot, went around things and caught their leashes on everything, one would go in front of me and the other behind me wrapping their leashes around me, it was annoying and sooo difficult to walk them... so now I take them on a more controlled walk, one on one side and the other on the other side and very little room for movement. After the walk, I take them to the field and let the lock on the leash go and let them run around with all 26ft of the leash! That way they got their walk and they got to run too! It works out soo much better for me and for them believe it or not, they really enjoy their walk when Im controlling their movements more.
Good Luck with her