I was born and raised in HK. 10 years ago, I married a Canadian. We had a child but have resided in HK. I am now in the midst of a divorce yet my child is a Canadian.
I would like to know if we do plan to move back to Toronto. Should I need to be sponsored by my child or are there any other options?
Your child cannot sponsor you at this time. Your child will be able to sponsor you once he/she is an adult and has worked in Canada for three years making sufficient income to meet the minimum income requirements for sponsoring a parent.
If you wish to immigrate to Canada, you will have to qualify and apply for permanent residency independently through an economic immigration stream like Federal Skilled Worker / Express Entry or one of the Provincial Nominee program.
Unfortunately having a Canadian citizen child does not entitle you to move to or live in Canada.