I did a BOM-DEL-EWR run last year (1 hr 40 min transfer time) but unfortunately my BOM-DEL flight was almost an hour late. This caused a great deal of hassle. I did make it but it was a difficult process. A great deal depends on the number of people in line at the transfer/emigration-security counters.

Since this is your wife's first trip to India, I would suggest getting a direct flight from BOM-YYZ and avoid uncertainties.