Looking at the photos, the plant appears underwatered. You will see that the leaves will feel a little floppy and get a wrinkled look. Jades like soil moist, but never soggy. You can check that water is reaching the root zone by inserting your finger 2-3 inches into the soil and see if it is moist. Often times when plants get crowded,the inner soil does not absorb water properly. These plants tolerate crowded conditions well, but may develop this water problem. Place the entire pot in a bucket or sink and fill with water about halfway up the pot, and water from the top. Let the plant sit in the water until the root zone is wet. Then remove it from the water (pot will be very heavy), and let excess drain from the bottom. You will not need to water it until the top 2-3 inches dry out again.

Otherwise, the plant looks pretty healthy.  The yellowing of the leaves indicates the plant needs fertilizing. Have you recently fertilized? Remember to  follow instructions on fertilizer use, as different fertilizers will have different reapplication rates. 

The plant has a lot of leggy side growth that should be pruned off.  Jades can take a some pretty heavy pruning to get it more into an upright shape. This will also prevent it from toppling over.