I'm assuming these are regular oranges. Sooner or later the cold is going to get them. January 13, 1982 we had a heavy ice storm. You may want to Google: Air Florida and Potomac to read about a plane that went down in the ice storm in D.C. to get an idea about the size of the storm and severity. The TODAY show reported that day there were snow flurries in Miami. There was snow and ice from Dallas to the northeast USA. The satsuma groves along the north Gulf Coast from Texas to Jacksonville were devastated and satsumas are usually more freeze tolerant than oranges. I would prune the dead stems and cover them now with a garbage can full of leaves. If they survive the next 5 weeks, let them grow this summer and pot them before next winter.

Meyer is the most nit-pinicky plant I know. I have 3 meyers and I have the same problem before. They are now looking very healthy. If I were you, that is if I were you I would dig that meyer and plant it again in a pot the same size as when you have it. Right now it is in shock and it may go if you are not careful. I think that being in a pot you can take care of it better. You can regulate the temperature for one thing and the pH of the soil. Dig it so you don't bother the roots at all. At this time it may have root rot by now. You said you damaged the roots while transplanting. You should have cut the branches off in proportion with the damage roots because one of the reasons you lost most of its leaves is because the roots can not sustain the leaves demands for water/nutrients because of the roots ' removal. It is not too late for you to trim more of the branches even when they are green. You will see they will bounce back with very green new buds once the tempt goes up. Don't believe the other's that you'll hurt the tree. Don't be afraid to cut the leaves and leave just a few. Second don't give any any fertilizer this time. The roots is not ready to take in fertilizer because it is still in shock. The less fertilizer it consumes the better it is. The first time you transferred it to a pot drenched the pot wiith lots of water. You want the salts and the fertilizers out of the soil at this time. Run a trckling water to the pot maybe 20 minutes until you can be sure all the salts are gone. Then put a transparent plastic cover over the plants and create a 3 to 4 holes as big as quarters on top. Now put it on the window sill but not in direct sunliight for about 5 days. Or until you see new buds are coming out. Then that is the time you can fertilize at 1/4 the dose. Use the miracid by Miracle grow fertilizer at 30-10-10 use for azealia/rhoddendrum/ camelia fertiler . Don't water it anymore until the 1st 2 inches of soil is dry. It is better to trim the tops right now to better serve the leaves by the remaining roots.Make sure the soil is every fast draining. A good mix is 1/3 sand 1/3 peat 1/3 top soil. I hope you don't have root rot at this time. Check it first. If your roots is still healthy I am sure your tree will recover. Treat it just like a sick child. Only clear liquids, no solids and rest. Lots of it.

Is your sister's tree the same cultivar? If so, (and even if it isn't), you should ask here how she cares for her tree first. There are so many variables that can affect how a tree grows...soil type, amount of water it gets, micro climate, fertilizer use or non use, proximity to structures, etc. etc. I planted ten rooted cuttings, all from the same mother tree, in my yard this winter. The variation in their individual growth rates is astounding. Some are well over three feet tall and have figs on them all ready. The smallest is only about 5 inches tall, and the others are at various stages in between. I'm sure some of the more experienced figgies will weigh in on this one...

It sounds like the location is good, they like indirect light. With any bonsai, water when it needs it, so poke your finger or a chopstick into the soil to feel for moisture. What kind of soil is in your pot? It should be a free draining coarse mixture, not fine soil . When you pour water over the top of the soil, it should drain immediately out the bottom of the pot. With good soil, you cannot over water. If the soild doesn't drain well, the roots rot and can no longer take up moisture. My indoor bonsai are potted in 100% Turface (Calcined Clay) and go between 3-7 days between watering, depending on the tree and the weather.