Welcome to FT.

Both International and Transborder flights arriving at YUL use the same Immigrations/Customs hall.

As pitz mentioned, it might be misconstrued if you're standing around waiting for a long period of time and not going through, but depending on the age of your daughter, you may be able to explain the situation. I would suggest waiting at the top of the stairs before the immigration line ups as everyone needs to go through that point.