To me it just indicates at one point it may have not been able to get good moisture so it started to consume whatever it had stored.
Just trim off those dried out parts and the healthy leaves you can set aside in a warm, bright light area, and it will grow new roots/leaves, so you have a new plant!
As for the mother plant, as long as nothing feels mushy anyhwere in its branches and trunk, especially at the base, and you use gritty well draining media with that container having drain holes, then all should be fine.
Typically, when you water, it is good to see excess water drain out, so it also flushes away excess accumulation of salt in the media. Then you do watering intervals, especially since the plant is being grown indoors, so its dry out time takes longer. Glazed containers makes dry out time longer, so to help you gauge if media is still wet, use bamboo skewers, poke the soil below and pull out. If it still shows damp, delay watering. I do not know if you added rocks below or just a mesh to cover the drain hole to save the soil, so it may also affect drainage. Anyhow, water will still drain, so always check the soil. It also depends on the ambient conditions around there. It is good the plant is near a window. It really needs as much light and warmth it can take. Jades are active winter growers, if given time to acclimate in Fall, they can endure outdoor temps even down to 30F as long as kept drier. But since your plant is more indoors, just let it enjoy more bright light and warmth. Do quarter turns every couple of weeks to even out light distribution to your entire plant. It would be really good if light orientation of that window is either south, west or east.
