Chairs can be helpful for healthy computering because a normal office chair is not meant for a person under 5 ft. Another thing is keyboards and mouses.
You should monitor your computer. The usage or time could also be something to help.
The way you sit really helps with healthy computering. Also if you have sun shining thrue you should probably close the curtains.
You should really have a good chair that helps you with your back support. Your feet should also be placed firmly on the floor. Wrists should not be to hard on the table either.
You should see what you have on to see if it is going to affect you while you are on your computer. You can also adjust your work patterns.