Steph, maybe Jemi' has some toy poodle? Molli can jump really high too, and she runs ALOT faster then Sammy does.
Possibly...I could see that...

She gets her energy, running and jumping ability from her terrier side!
Okay, I should've known that. I thought that even though rat terriers are a terrier, they aren't as active as others. I am not too good with that breed, and I am basing it upon the one that I knew. She was lazy her whole life, and was carried all over...that was the owners fault though as I think of it.