Did you show any property ownership or immovable assets before you got refused?
I received the same letter for my parents.
1) Money was not an issue.
2) I showed liquid cash in India, and my pay slips T4 in Canada and savings in Canada.
3) I did not show my parent's day to day banking, only savings account. That would have been a mistake as well, I should have shown day to day banking with income crediting, previous years income-tax papers. I FEEL that lack of ties to India were major factor.
I am going to re-apply showing property and immovable assets. I am going to apply for IRCC notes and then re-apply.
However in your case, returning to children would have been enough reason to return, unless the child is adult.