You can definitely apply and give it a short. But chances of her getting visa might be slim due to following reasons:
- Travel History: Even though she visited multiple Asian countries, this is not a strong case for Travel history as most visa officials look for travel to EU, Australia or US where applications/applicants are well scrutinized
- Lack of ties to India: since her spouse has passed away, she doesn't have strong ties back in India. Her Children (you and your brother) both are going to reside in Canada. So visa officer might view that she might not come back home to India after the visit. Property documents might help little bit.
Best option for your mother is to apply for a Super Visa, once you and your brother settle in Canada.
