You'd better prepare a consent letter for your child. See details in the following website.
Weblink: http://www.voyage.gc.ca/main/before/consent_letter-en.asp
About ticket, you should consult with airlines company. For a child below 2 year-old, you need to pay some minimum expense if your child won't occupy a seat. Definitely, you will need to talk to any airline company to find out their policy. For your case, when you book a ticket for your mother, ask travel agency about reservation for your child. In the meantime, check with airline companys. Hope this helps!
Weblink: http://www.voyage.gc.ca/main/before/consent_letter-en.asp
About ticket, you should consult with airlines company. For a child below 2 year-old, you need to pay some minimum expense if your child won't occupy a seat. Definitely, you will need to talk to any airline company to find out their policy. For your case, when you book a ticket for your mother, ask travel agency about reservation for your child. In the meantime, check with airline companys. Hope this helps!