At this stage, your child's brain is able to process things faster and even memorise them better, hence, when it comes to writing, now your kid's speed will be better than before. Kids this age learn about new topics at school about various subjects. Reading and writing is the basic need for school going children. You as a mother need to improve your child’s ability to write further so that they get better at it.
What you can do
You can work on the kid’s writing speed using different methods. The first step is to correct the grip of your kid’s hand on the pen or pencil. Teach him how to place the thumb and the other fingers slightly above the tip in order to attain a good grip.
Assist your kid in order to help him work on cursive style of writing. You can buy him a writing book that has text written in cursive form. Make the kid practice his writing in that book each day. Grid paper is another useful device to help the child write letters in a consistent size. You can also ask the child to take up the stopwatch challenge. This would help the kid to increase his writing speed.