1 I would highlight that although she doesn’t own a home she has lived with her eldest child in India (if she went to live with them after your father’s death I would include that too) and will always have a room in their home to return to. That both you and your sibling have been providing for her.
This will highlight the fact that she has a home to return after her visit to Canada and both her child in Canada and India are supporting her so there is ties to Canada and India.
2. I would include proof that she does have some savings/invesrments and would include her banking statements. Although your finances are more important in a supervisa proof that she has some of her own savings helps her application to show that she is not dependent on her children for every purchase.
5. You can highlight that you make significantly over LICO and if you have a good amount of savings you can highlight this. You can say that you have the ability to afford to pay for any emergencies that may occur while your mother visits Canada (for example a dental issue) and routine expenses involved with adding another adult to your household. If you own a home you can also say that you have an extra bedroom that your mother will use while visiting on a supervisa. If you rent you can also say that you have rented a large enough home so that your mother can have her own room (if that is the case).