Layover time in Montreal, Trudeau airport?

[udscoobychick]

Hi ladies. I was wondering if anyone is familiar with the Trudeau airport in Montreal. Is 90 minutes enough time to deplane, clear customs (coming from the US, flying to somewhere else in Canada), and get to the next gate? If it were for me, I wouldn't hesitate because I fly all the time, but it's for BF's son, who has only flown once before. Thanks!