BA is unlikely to make a change or refund the tickets when the arrival time remains the same and MCT is not violated. If you had been on AA-marketed tickets, AA might have done so as a courtesy, but even then a bit iffy.

Even with a kid, I don't consider a domestic connection of 60 minutes at PHL anything to worry about (presuming that you are arriving from a Pre-Clearance station in Canada). You have 45 minutes to make it from inbound to departure gate, even if the kid needs to make a "technical" stop.

There is also nothing which prohibits you from calling AA. However, as it is not the ticketing carrier, it is almost certain to refer you to BA.