I have posted a photograph of last year’s blooming jade plant and at that time I asked if anyone else had a blooming jade and whether they knew HOW and WHY.  No one responded, but I gather it is rare.  My plant is VERY old, spends half its year out on a porch with only morning sun, gets run-of-the-mill plant food at somewhat irregular intervals, ir about four feet tall and looks like a tree!  This is the third year that it has bloomed for me!