Mother extending TRV

I'm looking for advice from you all who have experience with immigration. My mother has been in Canada three years ago for 5 months and then again this year since July and we want her to stay. The reason I want my mother to get approved for an extension is that I want her to have a major part in my children's lives. She is living with us and watching them while my wife and I work. Though we are paying her expenses, we are not paying her a wage, therefore she is not here for work. This, to my wife and I, is very important. Is that a good reason for IC to extend her VISA? I'm afraid that they will say we are taking away from the childcare workforce by allowing her to look after our children while we work but it's more than that, we want her to be a part of raising them, not a stranger. Thank you so much for whatever advice you can offer.

Omar