The most likely components to be original are the stem, handlebars, seatpost, and brakes.
The rear derailleur freewheel/cassette and chainwheels are probably the first to be changed on a bike.
At least it would be the earliest date that the bike could have been made.
Of course, all this assumes the bike has the original component.
This is a Specialized Ariel Comp Disc ladies hybrid in medium.