No Chinese at my office desktop, sorry.
Suggestions:
1. check if the valve under heating outlet cover is fully opened;
2. let family members select own room by his/her room temperature preference
1)There are limited adjustion you could do on the vent.
2) put fan at ON, the temperature is more even
3) buy a electric heater.
4) buy a electirc baseborad(heater) and temperature control.
One option is to have an inline duct fan (a.k.a booster fan) installed in the air duct that goes from your furnace to the cold room. When the furnace starts, the fan runs and helps to suck up more hot air into the cold room.
It most likely be an air flow problem which means the air is not evenly flowing between those registers. You could make them even by closing the one of registers in warmer room a little bit if adjustable to force the air into the other room. (not fully closed) You may adjust few times to make it work.
Good luck.