? Beaches Turks & Caicos

Hi, My sister is interested in going to Beaches - Turks & Caicos, she
lives in Edmonton, Alberta and was wondering if flying through Toronto
/ Montreal is the only option.  Does it require an extra night stay or
just a connection? If so is the connection reasonable? She has a five
month old son so is a little concerned about taking him to Mexico and
is looking for an alternative. She and her husband also have two girls
so are looking for the easiest route. Any assistance would be
appreciated, Thanks Tessa