i got several jade plants. One quite huge one which I'll share a photo of some time if I remember. I have had leaves growing off a leaf and then making roots and being able to grow from the dead leaf as the base when it fell off, love it, it's a great plant. Chinese i think called it a "money plant" as they thought that the more it grew the more money you got, or some shit like that.
whatever you do. don't put it in a bigger pot (it doesn't like having wet feet). Maybe try to lightly aeriate the soil and then add some fresh stuff and give it a water and feed with something with a decent amount of n and trace goodies.....you know the script lad.