Good day to all.

This forum has been a great help for my successful spouse visa application a couple of years ago.
We are now in the process of getting all the requirements for my little one to come and settle with us. I hope somebody who has had successfully applied for their children to be with them could give us advise about the requirements needed, especially the proof of sole responsibility.
My child has been looked after by my mother and my father whenever my mother is in Singapore.
I have read that I need a letter from 3rd parties such as GP, School confirming that I am sole in charge of my son's well being. I have spoken to his School teachers and Principal and they would be happy to help but I was asked if I could just write the letter and they would sign and out seal on it.
Can anybody here please help me about what to write on the letter. Any advise would be very much appreciated.
Thank you