It sounds like you are doing everything properly, however, a soft, damp stem is an indication of root rot, which is typically caused by too much water in the soil. Does the pot that the plant is in have a drainage hole in the bottom? If not, water could be staying in the soil for too long.

In the winter, jade plants should be watered less often than in the summer. If you are watering approximately once a week, try extending that to once every two weeks or so. 

Another factor is temperature. How cold does it get by that window? Jade plants don’t like to go below 50°F at night and colder temps from drafty windows can damage some varieties.

Unfortunately, once a jade plant has root rot, it’s hard to get it to recover. Let it sit for a while without watering and see if anything changes. If the rot spreads, you could try cutting the stem above the rot and replanting the healthy part again. If you do, let the cut part sit in the air for a few days to form a protective “skin” over the wound, then plant it in dry soil.

If the fallen leaves are healthy, you can start new plants with them by placing them on top of soil, too. 

Generally, wrinkled leaves are a sign of underwatering. However, they can also occasionally be caused by overwatering, so we should first consider the conditions which led up to this point. Firstly, how long ago did you repot your jade? It’s a good idea to avoid watering right after transplanting, as this allows the plant’s roots to get properly established.

You mention that you don’t water much, which is good, generally. The important thing is to let the soil dry out completely between waterings, and to water deeply. Check if the trunk of the plant feels mushy at all. If so, this is a sign of rot (and overwatering). 

How much direct sunlight does the plant get in the window? Too much direct sunlight could be drying out the plant faster than normal, especially in the dry winter air. Additionally, how cold does it get near the window at night? Jade plants don’t like to get below 50°F at night, and should be kept away from drafty, cold windows.

With all that in mind, it seems most likely that your plant is too dry. Water it deeply and let it dry out completely before doing so again in a couple weeks.

Hi, Brenda: While we think of it, there’s a little more about shamrocks at https://www.almanac.com/content/houseplants-growing-tips. Meanwhile, sure, if you feel your shamrock is crowded, gently transplant it into a pot that is at least 4 inches larger in diameter and depth. Put some stones or broken pottery in the bottom (obviously, you would then set this on a dish or tray), then fill as needed with good potting soil. Shamrocks usually need to go dormant for a few months. As the leaves turn brown, clip them off leading up to this stage. Water only when the leaves first appear to wilt, usually once or twice a week. Thanks for asking!

The plants you are describing don’t really sound like jade plants (not yet, at least), but they may be a related succulent species, such as a pencil cactus. Only time will tell! 

In any case, you should let them grow a little larger before transplanting. Let them establish more foliage and get back to good health. The best time to repot them would be in late spring, when there’s more daylight and warmer temperatures. If they are indeed separate plants, it would be best to plant them in separate pots.