Thanks LondonElite! The individual in question (<3yr) is in fact travelling on a revenue ticket so I was sure Aeroplan membership was possible.
I see the "Aeroplan Kids" PDF form says 6-8 weeks and that you can accumulate when the number is received in the mail. OTOH signing up through the website is immediate (I assume)?
Travel is in about 8 weeks. Is is better to sign up through the web and forego the apparent benefits of Aeroplan Kids?
Thanks!
andrew