Shes got visa.. And a open work permit too
Then it's only a medical and personal reason. A heavily pregnant woman will not be allowed to travel, also according to the airline policy, you may have to get a doctor's assessment if she's fit to travel during later stages of pregnancy. If you're fine with bearing the cost of delivery in Canada then you can do so, there is no rule preventing you. If you want to deliver the baby in India you will have to plan for her to return early and then do the delivery there. I am not sure of the rules of having the infant travel but I am assuming some restrictions might be there.
On citizenship issue, your child will automatically be given Canadian citizenship if they are born in Canada although there is no benefit for you personally if you are raising the child in Canada it will be beneficial. Also applying for an Overseas citizen of India will give a Lifelong visa. Alternatively, you could seek Indian Citizenship but that would require surrendering the Canadian citizenship.